Hello Aspirant,

The government has notified six communities as minorities  Muslims, Christians, Sikhs, Buddhists, Parsis, and Jains.
To obtain the minority certificate, the process depends on the state where you live. Generally you need to approach Social welfare officer SWO of your district and he will guide you with forms and attachments. Here are few things to keep in mind when you go to obtain minority certificate:-

• All docs need to be True copy stamped
• Form Should be signed by local Talati
• Few states provide online form filling and docs submission (google it for your state)

Since you haven't mentioned your state i am unable to guide you exactly with full procedure.
Still I Hope this will be useful to you. Thanks.