Capital gain

Yes Exemption can be claimed

No deduction of capital gain is available to father. (Mere Sale of land is not covered under 54)

it's called deduction and not exemption under 54.

Option is to gift the land to your son's and then sale Of Land. Sale will be by your son's and they can purchase another land in their name.

Capital gain tax on land gifted will be in the hands of your son's equally.

Deduction allowed under section 54F if the net sale proceeds invested in purchase of another residential property subject to such conditions. Even residential property purchased in the name of sons also eligible for deduction based on case laws.

OR

Deduction under 54EC also available.