Process of indian marrying malaysian

Hi i'm a malaysian muslim who is going to marry an indian christian who's residing in goa. I would like to ask few questions regarding the process of marriage between us in malaysia.
I understand that in order for us to get married, my future husband need to provode single status certificate and no objection certificate from Indian Government. He went to various office on Goa to get the certificate but still unable to get the certificates. So i would like to know which department in India is it to get the 2 certificates? Or is it possible for him to get these certificates from indian embassy in kuala lumpur?
Next question is, since my future husband is a christian and he will be marrying a muslim, i understood that he need to convert prior to our wedding in Malaysia. However, i would like to know after he convert, will he need to update his religion status in all his legal and identification documents in India as previously i asked an officer in Islamic council in malaysia that he don't have to update his religious status in any of documents as he will be provided with a formal card saying he had converted to islam. I would like to confirm again tegarding this matter with experts here.
Thank you in advance for answering my questions