Property Distribution-2 Share holder are not willing to Sell.

I am son of My Mother (Expired 3 years back) We are a Muslim family. My grand father (My mother's father) property located in Kumbakonam (Thanjavur Distruct), he died long back. He has 7 children's (5 males & 2 females). All are got married (2 Males settled in the same house with their family for quit a long time atleast 20 years but others are settled in Chennai). After some time due to financial constrain 4 share holder (3 male & 1 female) who are settled in chennai are approached local muslim Panchayat located at Kumbakonam & based on various arguments, finally all the share holders except my mother are agreed to sell their share property to a fixed price. Based on that confirmation we have involved and bought the shares from the 4 share holder (3 male & 1 female) who are settled in chennai for the same price they have agreed with panchayat & done the registration also. Now when I approached the remaining 2 share holders (2 males who are settled in the same house for long) to sell their shares to us. They said they will give it to us for sure but asked some time to decide. But we waited for so long since 6 years. Now they are saying they need their share & they will not sell to any one. They occupied a complete home with their 2 family's. In between due to my financial constrain I sold my shares (5 shares-3M & 2F) to another party who shown interest on my property based on the trust that the remaining 2 share holders will give their shares to us. Now I am getting pressure from the other party to give the money back to them since these two share holders are not willing to sell their shares. Now I am in deep trouble & really seeks valuable advice to move forward.