Kattha for indiviuals

Sir, We are 8 sibling to our parents and 5 are sons and 3 daughters. My late father left a will which was probated and as per my mothers wishes the old house in which we were staying was demolished and 5 flats constructed before my mom passed away. I as the eldest son executed the will as stated in will. 1.The flats were constructed without approval from the CMDA and now for regularization process they have asked us to get individual Khatthas. As the construction was completed in 2005 and the partition deed was registered in 2012, how to get kathhas in our name as the khattha is in our fathers name and the Tashildhar says he will issue as per the legal heirs that is all 8 names. My sisters are not interested in the the property any more as the sale of some other property was equally shared in 2002.how to go about. 2.How to get the UDS certificate. This was inadvertently missed out in the partition deed. Can we amend the deed now. Is it required as we have inherited the property.Can the flat be sold based on the fact that this inherited and hence UDS may not be required. Please help us how to go about.