It's spoken out after a 72-year-old nun was gang raped in West Bengal last weekend. Police are looking for a group of six men accused of attacking the Sister.
The convent says the woman was raped as she tried to stop the intruders.
The men are also accused of destroying the convent school of Jesus and Mary in Ranaghat and stealing money.
Three other Sisters remain in hospital.
Neville Kyrke-Smith, National Director, Aid to the Church in Need in the UK, said: "We call on President Modi and all politicians to condemn attacks against Christians and to support religious freedom for all."
"This sexual violation of an elderly nun adds to the growing fear of Christian communities in many parts of India.
"The tension and acts of aggression in India against Christian communities are escalating as we see an increase in intolerance and a rise in a politically religious fundamentalism."
