Family property transfer through will

My father has five brothers and two sisters (Aunts).

Now only 3 uncles and 2 aunts are alive. My father also passed away.

We have one family shop in the name of my grandfather.

We don’t have any property received from our grandfather. My grandfather died before 1975.

My father and other uncle bought 5 acre agriculture land in 1980. Land purchase on name of my one uncle as he was unmarried. In year 2000 my uncle died and he made WILL document and transfer all land to one of my uncle. WILL is not register. In year 2002 my father also passed away.  No one of our family member not aware of any WILL or property transfer.

In WILL document uncle who died clearly mentioned that “he was doing clothing business and shop was on his name. ‘’ However, shop is still in name of my grandfather. He mentioned incorrect in WILL. Land property was purchase through combine income of all brothers and also from shop income as well.

Sell deed of that land is one sided deed and land owner from whom land purchase he mentions in sell deed that he received cash money from uncle(who made WILL).  Source of fund was CASH.

Current possession on land is of my uncle who received through WILL by my other uncle.

We get to know of WILL in year 2017. Till date we don’t know about WILL and also property transfer. Uncle (beneficiary) always only tells he will going to distribute but never distribute land. He started various businesses on land but never shares profit with family member.

In year 2017 he (beneficiary Uncle) decided to sell the whole land ,so he invited us (my other brothers for meeting only). However, he sells all land directly to developer and not give any share to us. Now he refuses to give any share. And that’s the way get to know about WILL and property transfer and his intention.

Below are the key points :

1. We are Hindu family
2. We don’t have any partition in family till date.
3. Shop is still in name of my grandfather.
4. In WILL all signs are very much differ.
5. WILL is not register. Only noterised.

My questions are :

1. Is land is Joint family property ?
2. How my uncle transfer whole land to only one uncle through WILL ?
3. How I proceed can I ask for partition?
4. Also, I believe WILL is fake. So I directly challenge WILL?

Please guide me.