Dad transfered all his property to his son alone.

in case Property in question is self earned property than your late father has all right to dispose as per his will.

if you have doubt about authenticity of WILL than you may challenge in Court

You have not informed whether the property in question is self acquired property of your Father or otherwise. In case, the property is your Father's self acquired property, he can do whatever he wants to do with the peroperty and Will it to anybody he wishes to and he need not as much as inform anybody leave alone discussion.

 

However, if you suspect the veracity of the Will as to the mental condition of your Father as it was made just two monhts before his death, or you suspect that your Father's signature was forged, you can file a case accordingly questioning the validity of the Will with all proof to support your allegations. Merely saying that your Brother managed to get his name alone to be inserted into your Father's will not help you in Court. You have to go to Court with all proof.

Try to enjoy that you have your mother, your brother has money only.  (like mukesh ambhani.)

If the property is not ansestral and self owned of your father then he can give it  to any one

You need to confirm about what you doubt in execution of will.

Typical Indian family each fight and get disgust of not getting any share. we Indians have no self confidence to earn wealth we simply talk that one fine day we getlottery and become reich we waste our time money energy everytihing. If u challenge it in court it takes 25yrs to finish.so u do u issue legal notice if they refuse file suit if they come to compromise compromise don't drag it .if u want to drag then engage minimum charging advocate.

If there is some legal issue or doubt qua execution of the "Will" must be challenged. 

Show the document of "Will" to a local prudent lawyer for better appreciation, guidance and proceeding.

in case of self acquire property your father had full right to give it to any one however if he had acquired it from ancesostors or funds by selling ancestral property daughters can claim
feel free to whatsapp or call if any doubt left