Long term capital gains tax

First ascertain whether it's rural agricultural land ?
if so, then there's no need to worry about tax bcoz it's exempted income

if it's not rural agricultural land and it's urban agricultural land, then you can invest the entire capital gains amount in another agricultural land. (agricultural activities should've been done for minimum 2 years immediately preceding the previous year in which your land has sold.)

if it's neither rural nor urban agricultural land, then invest the entire net sale consideration in any house property.
or
invest the capital gains amount in the any notified bonds within 6 months from the date of sale

or

deposit it in capital gains account scheme on or before Filing return of income (the Amount should be utilized to purchase the aforesaid properties (except bonds) within 3 years from the date of sale) or it'll taxable in the year of maturity or in the year of premature withdrawal from whichever is earlier.

hope this will suffice

Firstly Defined nature of land whose sold by your father

The nature of land agricultural land.
It is not mentioned.
Capital gains arising transfer of capital asset.
Tax cover is available..