Its not Compulsion to have a Lawyer while making Rent Agreement, though it is always recommened to take Advice from the Legal Experts.
There is a prescribed format for Rent Agreement you can download it and can change accordingly to your agreeement after that purchase the stamp paper by paying the stamp duty fixed by the Government in your state, sign the Agreement in front of Notary Public and make it attest from Notary.
You can check this blog to know more how to make rental agreement- https://www.edrafter.in/make-unregistered-rent-agreement/
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https://www.edrafter.in/