How do I add my name as a Co-owner of a flat where my mom is a single owner?

 How do I add my name as a Co-owner of a flat where my mom is a single owner?

Answer: To add you as a co-member in the flat of a CHS in your area, your mother should do a gift deed by gifting 50% of the value of her 1BHK flat to you. On this gift deed, 1% of the government market value of your mother's flat will be the payable stamp duty and Rs200 registration charges will be applicable. 

With a copy of such a registered and stamp duty paid gift deed and its index-2, you can apply for co-membership on the form available in appendix-5 of the Society's bye-laws book of 2014.