Christian couple married 30 years ago, where should they get marriage certificate?

Case: A Christian couple married in Delhi about 30 years ago, and received a marriage certificate from their church in Delhi under the Indian Christian Marriage Act, 1872. They have since been residing in Noida, U.P. and all their ID proof is of Noida. As per the visa process for travel, they are required to submit a marriage certificate. Questions: 1. If Christian marriage certificates are considered valid under the above Act, does the couple need to have a government issued marriage certificate too, or will the church issued marriage certificate suffice for the visa process? 2. If they do require the government issued marriage certificate, would the same be available at the local marriage registrar’s office as the marriage was solemnized in Delhi, and as per the Act, the details of all marriages conducted by the church need to be registered at the registrar’s office? 3. If they they do need the government issued marriage certificate and the church issued marriage certificate will not suffice and is not available at the local marriage registrar’s office, then which location should the couple apply for issue of a marriage certificate, since they got married in Delhi, but have been residing with ID proof of Noida? Would be grateful for some advice on this. Thanks