Building Collaboration/Agreement conditions Breached.

Owners had collaboration Agreement with Builders. With Govt. permitting G.P.A. Registration. Builder sold his Floor share by negotiating a party that paid consideration by Banker checque plus cash as told. In such a situation Registering Authority may/may not insist for original property documents & sale got registered. Owners had construction issues that Builder was to perform as per Agreement.Builder was gaining time inspite of reminders verbal, through e.mail & through Speed Post as well. Builder never replied in writing & always evasive. Recently when purchaser was to occupy sudden he got some work started & suddenly stop. Contacted through Phone not available. Owners are interested in performance of conditions of Agreement. Initial Owner/Builder Agreement for Property Development signed Aug. 2011 [Unregistered] G.P.A. for this with consideration Registered October, 2011. Construction Completed Dec.'2012. Penality clause in Agreement Rs.1.5Lakhs. per month for non completion. Since owners share were incomplete Possession Letter signed in May, 2013 & handed over to Owners. Still Basement was wet for that M.O.U. was signed [May, 2013 - plain Paper Builder affixing his stamp& signed] between owner/Builder in case with all efforts Basement remains wet Builder would Pay rent [undisclosed] more than 26 months passed not paid single rupee plus electricity that would be consumed till Basement gets dry. These are some of the examples Owners if they want to have the entire work done Lakhs of rupees would have to be spent in repairing defective construction/replacing costly material & so on. Our Question is if suit is filed now whether we can have our contract condition got fulfilled- Simply everyone will say yes to this we want to know shortest time since we are senior citizens-75 running [kindly guess our limitations health & age] children being serving abroad struggling to establish no help expected. Can rent be recovered early then how much time if we get. similarly, can we got removed non-compoundable construction to have it reconstructed with in permissible by-laws of M.C.D. Please quote time & fees payable if someone guarantees both i.e. Time Bound Solution replacement/repair & Owners compensation from Builder. Thanks.