Capital gain on sell of shares

Dear All,

I have a query regarding capital gain tax on sell of shares.

My grandfather had some shares in his demat account since very long time (all the shares are held for more than one year). Now after his death we replaced the name of my grandmother in his demat account (so now all those shares are in the name of my grandmother).

Now we want to sell all those shares within 5-6 months from the change in the name of demat account holder.

What will be the tax implication in this case? Will there be any STCG liability arises in this case? Also mention the relevant section number.

Thanks in advance