First we need to understand the difference between Cooperative Group Housing Society & Welfare Society . CGHS as you all know , coz of previous scams DDA has abolished that norm to provide land to CGHS , now its very fair practice to be a part of Welfare Society who is registered , some will argue here thats not a big deal , anyone can make a Welfare Society by few bulks and start doing all this . Here make it clear if that society is registered according to DDA's norm & read they MOA ,bylaws before entering into it .By laws indicates how transparent that society is ! A welfare society can collect land cost , develop group housing for its members . Its not mandatory to buy land first, society can buy its land after collecting land cost from all members, but for safer situation it is must to buy land then finalizing a particular a fixed land cost.For this you need to have fund , here comes the role of promoter .