Is San Thome Church, Chennai, the second oldest church in India?

San Thome Church.Mylapore, Chennai,Tamil

Interior,San Thome Church.Mylapore,
Martyrdom of St.Thomas,Chennai, paintings by Peter Paul
St. Thomas Didaemus (meaning "the twin''), one of the 12 apostles of Jesus Christ,  is believed to have visited Musiris (Cranganore) in Kerala, South India in 52 AD. He first started converting the Jewish traders living there and later Hindus in  Palayur,  now a town in Trichur district, Kerala. In order for the local Christian community to engage in prayer and carry out certain Christian services,  he built a small church with an altar and later he consecrated it. Subsequently, he is believed to have built seven and a half churches across the south Malabar coast, one being in Kanyakumari district of Tamil Nadu. This is supposed to be the oldest church in India, one of the oldest in the world!!
Shrine of St.Thomas,Mylapore,Chennai,18th-C print.
St. Thomas altogether stayed in India for 17 years, 4 years in Sindh (now in Pakistan), about 6 years in Malabar Coast and 7 years at Mylapore, Chennai in Tamil Nadu.  St. Thomas later settled in Madras (now Chennai) in 64 A.D after his long journey to China. At Chennai, the apostle is said to have stayed at a small village what is now part of Mylapore.

In 72 A.D., St. Thomas, as ill-luck would have it, had a tough time with local authorities. Bad luck seemed to have haunted him far beyond his expectation. He was killed in a nearby hill where he sought refuge. The hill is now called St, Thomas Mount, an important suburban area of Chennai. He was mortared there and a  church was built in his honor.
The Palayur church first built by St Thomas in Kerala, is still very much in the same place and at the same site and is the oldest church in India. In the 17th century, Rev. Fenichi built an outer building surrounding the old church because the old wooden walls were completely damaged. However, he did not touch the original altar consecrated by St. Thomas, centuries ago.  

The second oldest church in Chennai is the San Thome Basilica built over the site where St Thomas’ body was once buried. In the sixth century, Armenian Christians discovered the grave of St. Thomas and built a church on the site in present day Mylapore. The Portuguese, first European settlers in India found the old church in ruins when they arrived in the 16th century. In 1516, they built a new Baroque-styled church and called it the Lazarus Church. After seeing the burial ground there, they took so much pain and built a beautiful church in 1523 on the Mylapore beach and called it San Thome, after the apostle. Now, San Thome Basilica is an important landmark in Chennai city.

In 1606, the Diocese of San Thome was formed. In 1893, it was rebuilt as a church with the status of a cathedral by the British. The Neo-Gothic style was introduced by British architects in the late 19th century.

At the Basilica in Chennai are kept a small bone of his hand, a portion of bloodstained earth and head of the lance, which struck him down. The main remains of St. Thomas were later shifted to Ortona in Italy where they remain to this day. According to tradition, in 232 AD, the greater portion of relics of the Apostle Thomas was said to have been sent by an Indian king by the name of  "Mazdai" and brought from Mylapore to the city of Edessa, Mesopotamia.  
San Thome Basilica(16th C) built over the tomb of St.Thomas.Chennai,
To honour the historic arrival of St. Thomas in India in 52 AD,the Indian Postal Service of the Government of India brought out two commemorative stamps, in 1964 and 1973. In recognition of his  most valuable services and unselfish missionary work  St. Thomas was proclaimed 'The Apostle of India' by the Holy See. Likewise, the oldest historical Protestant church in Asia is Church of St. Mary, located in the Fort St. George, built by the East India company. 
St Thomas Syro-Malabar Catholic Church at
India also can boast of the oldest Protestant church in Asia consecrated in1680 by the Chaplain Rev. Richard Portman. This is also located in Chennai,within Fort St. George, first built by the East India company to carry on their mercantile trade. Later it became their military base. The church was called the Church of St. Mary  because the foundation stone was laid on the Annunciation Day of the Blessed Virgin. The first marriage recorded here was that of Elihu Yale with Catherine Hynmars on November 4, 1680. Yale was the former Governor of Madras, British East India Company. Yale University in the USA is named after him because  he donated a large sum of money initially for the establishment of Yale College. Yet another famous man got married right here. He was none other than Robert Clive, who laid the strong foundation for the growth of the British Empire and inherent imperialism.
Interior- St Mary's Church, Chennai.
 Above image: It shows the Interior- St Mary's Church inside Fort St George, Chennai.It is the oldest Anglican church in India/ Asia

St. Thomas is the only church in Asia, and one of the very few in the world, built over the tomb of an apostle of Christ. Atop St. Thomas’ Mount is yet another  Church dedicated to Our Lady of Expectations and it has an oil painting on wood, of Virgin Mary with a child. St. Luke the apostle is believed to have made it. It is mentioned in writings dating back to 1559.

Though Christianity was established by 72 A.D, it was only after the arrival of the European and North American missionaries in the 16th century the Christian movement throughout the rest of India saw favorable progress.

Today, there are over 35 million Christians in India both Catholic and non-Catholic, with the maximum number in Kerala. In Tamil Nadu, Missionaries such as   Roberto de Nobili, also known as Thaththuva Bothagar, Constanzo Beschi / Constantine Joseph Beschi, also known as Veeramaa Munivar, Bartholomaeus Ziegenbalg, Robert Caldwell, George Uglow Pope,  Christian Friedrich Schwartz,  et al won the heart of local people while on their missionary work. All of them gave importance to education and job-related skills and never indulged in forced conversion of the natives.

Indian Christians, depending on the place where they live too have neither given up their roots nor their family traditions that have very strong Indian flavor. Being true to their religion, they celebrate weddings, Christian festivals,  etc without compromising on their dress code and Indian legacy and culture.

As for San Thome, Basilica Chennai, perhaps, it may be the second oldest Church outside of Kerala.

Ref: /wiki/San_Thome_Basilica