I have let out my Chennai house to a tenant for residential purposes since 2004 under a 11 month lease agreement signed in a Rs 20/- stamp paper and had been extending this after every 11 months in Rs 20/- stamp paper. Actually the last extension expired on 31st May 2010 but due to preoccupation I could not get the extension agreement signed in a Rs. 20/- stamp paper. Is it okay I get the agreement signed in Rs 20/- stamp paper dated 24 July 2010 in which the effective date of extension is from 1st June 2010 - meaning extension with retrospective effect? Appreciate clarification.