Parking alloted in the agreement is not showing approved in MCGM Plan.

Dear Sir This is with regards to our parking which have been changed multiple times during our redeveloped flat possession exercise. We were alloted original parking no 23 in registered agreement as amenities, post which we were alloted parking no 48 during possession and subsequently changed to parking no. 53 post possession one month later. We co-operated with the builder and accepted all the multiple changes and also we have parking allotment letter of each time the revision was made. Now we have been brought to notice that parking no 53 is not a part of the MCGM approved plan and hence is illegal. Kindly request you to guide us how do we take action and proceed to get a legal parking space from the society/builder.