My uncle's is not surrending my grandfather assest to me

Gud eve sir since last 20 yrs we are join family. now we are splited. my age is 22 shall i file a case against my uncle ( my father's younger brother. she was born to my grand father's second wife ) ? my grand father is died on 2011 after my grand father's death i asked she said k no problem let we share our assest on that time i need to join college due to this matter my concentration move to study now i compledted my degee and now i asked my uncle to give my share but now he is not surrending my share to me . my dad is not intrest on that land but i need my grand father's land i have one main doubts what means during 20 years my uncle owned my share now am eligible to file a case against them. pls help me and give good idea sir and one impartant mater sir my grand father (suburayan) has two wife. first wife ( athimal) she had two childern (my father (murugesun) and ( my anty thenmozhi). second wife is ( bownamall) she had four childer ( 3 boys 1 girl) all the proprty is named to uncle during my grand father alive now they share the land between.