Cancellation of will?

The promissory note is not valid and cannot bind the testator not to revoke the will later if he so desires. Any written undertaking obtained from him ex-facie indicates that it was obtained under pressure or exerting undue influence on the testator. 

Originally posted by : KUNAL

so what is your query exactly?

I have written a will in favour of my brother & i registered it few months back. The property is my self earned property. Today my brother asked me to write in a 10₹ stamp paper that i am writing this without any one influence and i will not revoke the will in my life time, and he asked me to sign in this stamp paper and took it with him.

Now do i have right to revoke the will in future?

Such assurance, even on stamp paper, is of no legal validity. You can revoke the Will at your discretion. To revoke a Will, it is not even necessary that the testator need make a document to that effect. If he make a subsequent Will, the earlier one would be rendered obsolete and stands revoked.

Testator has right to  change ,cancel or to modify will and also  he  can dispose will properties  and make zero validity of will .