This Marriage is governed by Special Marriage Act 1954 as it might come under different religions of both husband and wife.
Documents needed for Online marriage certificate in India between an Indian and a foreign citizen under the Special Marriage Act:
Birth certificate for both parties (in English)
Passport for foreign citizen
The foreign party will need a visa for more than 30 days
Proof of address (for indian citizen)
Certificate of No Impediment/ Single Status Marriage Certificate
Passport sized photographs