Apartment blues

Apartment, 8 dwellings. association is formed but not handed over to members over 13-14 years so no office bearers and meetings nor accounting, poorly maintained, Builder has mentioned in sale agreement and conveyance deed about future 5 th floor, 2 units if he gets TDR, and mentioned about the share of future 2 units to be built even when actually only 8 are present at this moment., now he wants to built 2 units. q1. does he need permission of all those 8 owners as association ( he his trying individual permission). q2. since it is 13-14 yrs since he has constructed, does it need structural audit. q3. since area of plot is > 500 sq met and units >8, does he need to take MAHARERA registration q4. what are the options before the owners- official and legal. can we approach RERA q5. only 2 owners are staying, rest are rented, rented unit owners are largely investors and think conveyance of flat unit is more than sufficient. q6. the terrace is shown as restricted area in conveyance deed and in the deed of apartment even after future construction of 5 th floor 2 units,is this correct as per apt act.