Can a brother sell half of property when another doesnt want

you haven't discussed properly helping replying satisfactory.

Actually sir !! my father is three brothers , the eldest one was unmarried and my father is son on second number and the uncle want to sell property just for liquor is smallest one..

the property is still in name of the eldest bachellor brother who died befor 4 years.

1 ramesh -- died -- property is still on his name
2braj-- my father
3kamesh-- liquor addict

we also have a written statement signed by both living brothers and few more as proof that tha desire of rames is not to sell property and uncle kamesh have sign on that..
 

The property is the property of the grandfather or grandmother ?

 @cyber lawyer sir its property and house of eldest son ramesh only who is died now.. he alone purchase and build the house and on every documents there is his name only , and he died in bachellor (unmarried)
 but my father also helped by money , but it can't be proved on documents.

regards
 

The property purchased and still remaining on the purchaser i.e., your father's eldest brother's name will devolve upon his surviving class II legal heirs, in the instance, it is your father and his younger brother.  Since your father has an equal share in the property, he may ask his younger brother for an amicable partition of the property among themselves, if he is not agreeing to it, yur father can file a partition suit before the court of law and along with the suit to file an application for  injunction restraining your uncle from alienating or encumbering the property in any manner till the disposal of the suit, this will preserve the property from being sold or encumbered in any manner and you can be worry free about the property till you get a court decision on it.

I agree with the view of  kalaiselvan sir.

@ rohit kumar - If your father's contribution cannot be proved, then your father is entitled to equal partition as rightly pointed out by Kalaiselvan sir...

@T. Kalaiselvan, sir and @ cyber law sir ;

i have heard that if brother wants to purchase i.e my father wants to purchase the remaining half then he can not sell the proprty to someone else.. 
upto how much extenet it is true ? law of preemption

You have been wrongly guided abut the applicability of the law of pre-emption by someone to this issue.  It will not be applicable to such issues as the one being referred here.