What is the fate of sale deed and will?

We are two brothers and two sisters. My father had made will of a house in favour of brothers. Will was read out infront of sisters and two witnesses. Father is no more. Will was made by notary. On the basis of will, myself and my brother made a sale deed with one party ( buyer). At the same time we have applied for mutation that is to transfer the property on our name as per the will, with due information to sisters. On getting information through city survey office, one sister and sons of other sister ( who is no more). challenged mutation and also the will. City survey office gave decision in our favour. They (sisters) challenged the decision in civil court. Case is pending with interim injunction on the property by the court. On the other side, buyer is insisting to honour the sale deed which is not possible due to interim injunction. Three years have completed for sale deed. Buyer is trying to file suit for completion of sale deed. I want to know- 1) What is the fate of sale deed? 2) What is the fate of Will? 3) Can the sale deed be null and void?