ltcg on sale of residential plot

I purchased a plot forts.22000/- during 1987
Now I am selling the Sam for rs.6200000/-.I have to calculate cii for arriving,actual capital gain.In the budjet govt has annownced the base year for cii as 2001=100.I am now in a confution how to arrive cii value for the property purchased in 1987.State govt has already annownced the guideline value in their website from 2002 onwards.Accoring to this my land value as on 2002 is rs.589000/-.Can treat it as fair price index as the base value as on 2001and calculate cii value as this date.I want to have your clarification/advice.