1) if your uncle is refusing to agree for partition issue legal notice to your uncle for partition of 2 lands by metes and bounds
2) if uncle refuses your mother , you and your siblings can file suit for partition for division of lands by metes and bounds
3) please note that on your father demise your father share would devolve on your mother , you and your siblings
4) you have not mentioned how father share was transferred in mother name
5) have you and your siblings executed gift deed or relinquishment deed ? If so your mother would be owner of your father share
6) suit for partition would take over 10 years to be disposed of
7) better arrive at an amicable settlement with your uncle