Gift deed for amount received by DD

My mother, 67, who is a housewife, received an amount of Rs. 15 lakhs from her brother by way of DD in January 2020.

Now, while filing IT returns, will I be charged any tax? What if I make a gift deed for the amount? Can I upload it on the website while filing returns? If so, what is the prescribed format for the deed?

Additional info- I, her son, am a State govt employee in Goa. My income is not taxable yet. My father, is an agriculturist.

Your guidance will be appreciated.

Thanks