1. You can execute and register a gift deed/relinquishment deed in favour of your mother,
2. Thus you will gift or relinquish your undivided and undemarcated share of your grandfather's property,
3. To be more specific in the matter, you can file a partition suit to get the property divided and demarcated in your names after which you can gift or relinquish your partitioned property in favour of your mother.