grand mother can execute registered relinquishment deed to relinquish her share in property 

2) if  grand mother does not execute relinquishment deed or gift deed on her demise intestate her share would devolve on 2 daughters and your family 

1. If your grandmother executes a WILL bequeathing her 1/4th undivided share in the property to you and your brother, then after her death, the property can be registered in you and your brother's name.

2.  In case your grandmother does not execute a WILL and dies intestate, then her 1/4th undivided share in the property gets divided equally between her two daughters, you and your brother.

Yes it can be registration in the name of alll legal  heirs or as per the agreement between legal heirs 

You can obtain a registered release deed relinquishing her rights in the property by your grandmother which will enable you to sell the property properly. 

If she dies before that then her share in the property shall devolve equally on her own legal heirs including you both 

Dear client, according to hindu marriage act the grandmothers property can be inherited to her legal heirs i.e her sons and daughters. After the death of your grandmother the property will got her 2 daughters.

- As per law, after the demise of your father intestate , his property would be devolved upon all his legal heirs equally including his mother i.e. grandmother

- Hence, your grandmother can release her share in your favor after executing a registered relinquishment deed to make you both the owner of the entire property. 

- Otherwise, after the sudden demise of your grandmother her share in the property can be claimed by her 2 daughters. 

After your father's death, his self-acquired property devolved equally upon your grandmother, mother, you and your younger brother, each of you entitled to 25% undivided share. After your mother's death, her 25% undivided share passed on to you and your brother equally. At present, the undivided share in your late father's estate is as follows: 1. your grandmother - 25%, 2. your brother - 37.5%, and 3. you - 37.5%. After your grandmother's lifetime, her 25% undivided share shall devolve on her 2 daughters equally, and NOT upon you and your brother. In other words, after your grandmother's lifetime, the undivided share holding in your late father's estate shall be: you and your brother - 37.5% each; your two aunts - 12.5% each. This is the legal position.

Yes, by operation of law the property will come in the name of both of you(brothers) after the demise of your grandmother. However, if you want ownership rights to be transferred immediately, you both may ask your grandmother to do a gift deed 

After her demise, her share will partly inherit in her daughters. Better execute the WILL.