1) judgments depend upon facts of each case

2) it is self acquired property of grand father

3) on his demise in 167 property would devolve on C , D , legal heirs of A , B

3) your father one foruth share would devolve on your mother and children

4) similarly on B demise his wife and children would inherit his one fourth share

5) sale of land in 1976 could not have been done by your mother , aunt , C and D as children also had share on demise of their father .

6) within 3 years of attaining majority you should have challenged the sale

7) gift deed to be valid has to be stamped and regsitered.

8) transfer of land in favour of uncle D and aunt was fraudulently done

9) you have rightly challenged sale of land by aunt D and her son

10) you have good case on merits

On the demise of your grandfather his property devolved on all his heirs. The share of predeceased children devolved on their legal heirs. The remedy for you was to challenge the alienation and seek a declaration of your share, which you seem to have already adopted. We do not know where you stand in your case unless we peruse all the case related documents. So ask this question from your lawyer. If there is inordinate delay in the disposal of your case then you can move the High Court to seek appropriate directions.

This property belonged to your grandfather and upon his intestate death, your father's share (who to died intestate) shall devolve on his own heirs, that way you are entitled to a legitimate share out of your father's share as a right.

However since the properties were alienated through various registered deeds or transactions which were in your knowledge, any claim in that aspect now shall be barred by limitation.

Since you have filed the suit (nature of suit is not known), you may wait for the development and the judgment.