Bhai. This step was taken by the Delhi Govt. under Smt. Sheila Dikshit. This is what you are referring to I believe?
Section 81 was repealed last year.
I can't paste links.
Check this. Tribune Newspaper Delhi. Dated 16 June 2013.
/2013/20130616/delhi.htm#1
Ch. Satbir Singh, a prominent Jat leader of the Congress Party in Delhi, previously 3-time councillor from Mehrauli and Former Mayor of Delhi(2005-2006) took an unprecedented step in his tenure as the mayor, keeping in mind the welfare of "Dilli Dehaat". He got property tax exempted on...