Daan given by nanaji

In the year 2009-2010, my Mamaji had tried to sale my nanajis house as he need money on urgent basis. My nanaji have asked my 2 masiji to purchase but both were not in the position to purchase the property. Then my nanaji have asked my mother to purchase the property. As the total area where tge property is located have only registration permission but can not transfer in books of records (dakhil kharij) so we were not able to take a housing loan on the said property. So we have mortgage our Gujarat property and give the money to nanaji. At that time property cost was 10 lac. We have given 8 lac and out of 8 lac 1 lac each is given to my both masiji and remaining 6 lac is given to Mamaji. My nanaji have informed that we have paid 8 lac but 1lac which is not paid by us is my mom's gift by nanaji so property amount paid by us will be consider as 9 lac. In 2011 my nanaji have registered the property in my mom's name as Daan nama. But have not mentioned the movable thing in my mom's name. Since 2011my nanaji was staying in that house. Now my nanaji is died six month back. In that house one portion is in our position and one room was locked and the key of that one room is with my nanaji. In that room some of the things like box, some utensils etc pertains to my mom.Kindly guide us can we breakopen the lock or not as the property is fully in my mom's name. Kindly guide and if we breakopen and take position then what to do further.