Consequences of being a witness to an inter religious marriage

I am a 29 years old man and a close friend of mine has asked me to be a witness to his inter religious registered marriage in the near future with his girlfriend. My friend is 30 years old and although he is a native of Andhra Pradesh, he was born and brought up in Maharashtra. He is a registered voter in the state of Maharashtra and is a Hindu by religion. His girlfriend, who is 26-27 years old and is a Jain by religion, was also born and brought up in Maharashtra. The girl's parents are objecting to her marriage with my friend. The marriage will be held and eventually registered in Maharashtra. And therefore, I have four questions: 1) What procedure does my friend have to follow to ensure his inter religious registered marriage with his girlfriend is compliant with all the local/national laws? 2) What procedure do I have to follow to be a witness to an inter reigious marriage (Hindu groom and Jain bride)? 3) What legal consequences can I face for being a witness to a inter religious registered marriage where the bride's parents have strong objections to the marriage? 4) In case I sign as one of the witnesses and my friend doesn't follow the due inter religious marriage procedure in accordance with the law, can I be liable to face any legal action from the bride's parents?