Validity period of registered propert

We are landowner and we made registered redevelopment property agreement with builder in 2013. Since 2013, there are no action taken by the builder to actually start redevelopment work on a field. In agreement, builder have mentioned that after deconstructing our old house, if within 2 years, if he fail to redevelope property, then agreement terminates. Now here is a tricky statement in agreement, he can deconstruct our old house lets say after 20 years also so in other way this tricky statement don't have any maturity/validity period. And we have signed this document and it is registered too. In 2016, we have sent notice to builder to cancel the agreement but there is no response from him. So i want to ask If there is no time period/validity period is mentioned in agreement then is there any by default validity period with the help of which redevelopement agreement automatically terminates if there are no action taken by builder to start redevelopment work. If we want to approach to other builder to redevelope property what necessary actions need to be taken.