Transfer of property with the help of registered Will.

hello, Sir/Madam - my father done a sell agreement with a dealer on dated 14/2/2011 and take a token money of 20lac and apply noc in estate ofc Chandigarh but after a week he change his mind and ask dealer that i don't want to sell my home so plz. take your money from me as u gave me a token money (20 lac) but dealer refuse to take back and want home(property) after so many arguments and after couple of weeks he ready to take his token money and come at my home and take money from my father and burn the agreement and cash receive receipt after a week he demand to sell the house(property) my father shocked and said i already return your token money but the dealer refuse and said u don't gave me any money and show the copy of agreement to sell then later my father come to know that he take his token money and destroy colored photostat documents and keep original after that my father try to transfer the property to my mothers name but it was in-vain estate ofcl chd. refuse transfer and send a letter to decide from court the dispute between my father and dealer ..my father not go in court and the dealer also. in june2014 my father died and left a registered Will(dated 22dec2005) in the favor of my mother now my mother submit all the essential document in estate office chd. it already take 6 month but the said property is not transferred in my mother name estate ofc chd. make a condition to get NO OBJECTION CERTIFICATE in the shape of affidavit to that dealer Now the dealer not file any litigation regarding that agreement from last 4yrs. till date no litigation is pending in any court.WHAT CAN I DO THAT ESTATE OFFICE TRANSFER THAT PROPERTY TO MY MOTHER NAME BY THE HELP OF REGISTERED WILL.....SEEKING FOR YOUR VALUABLE ADVICE