Gifted shares cost

My grandmother had 1000 shares of rs 50/- each in her name (year 2000) so 50,000 rupees original cost

On death - 2023 - my father and my uncle received half each - so 500 shares each

Market price - 120 rupees 

My uncle gifted me 250 shares. 

What should I put as my cost? (should it be 120 rupees? / should it be 2018 fair market value? Should it be 0? Or other?) - from angle of taxability of I sell part / whole of the 250