0How to Obtain Caste Certificate in Mumbai for Hindu/Gujarati/Jain ?

It is seen apparently from your question i.e.you have written a almost a religion and not a caste i.e Hindu and Jain are  a religion and not a caste.  It seems your religion is a Jain.  In Hindu , there are so many upper caste and lower caste covered.   Caste certificates issued  only for lower caste people and not to upper caste people.  As per Hindu Succession act , Jain, Bhudhist also covered under this act.  Caste certificates are issued by the Tehsildar and  SDO i.e Deputy Collector in some cases.