Stamp duty on promissory note

Stamp duty is a State subject which differs from a State to another in India.

No stamp duty is attracted for a promissory note.

Dddear sir, I meant stamp paper.

In this forum itself some people said it is 1 ruppee revenue stamp for on demand promissory note and something else for a promissory note with due date. Somewhere I read it is computed by value of the amount and somewhere else it is mentioned that it is a flat rate of 100 ruppee NJ stamp paper 

Although I could have  posted here  I posted in a different thread asking if a promissory note or loan agreement executed can be enforced in another state. 

Please advise.

Promissory note written on a plain paper duly signed by executant (borrower), affixing one rupee revenue stamp is a legally valid instrument.

There's no necessity to execute it on a non judicial stamp paper even irrespective of the transaction amount.

It is only one rupee revenue stamp to be affixed. However, 2 independant witnesses must be there to attest the transaction / document of promissory note.