There is a whole thread on that discussion.
http://forum.valuepickr.com/t/buy-unlisted-shares/
Also please subscirbe to Alpha Ideas News letter. Raoji occasionally send email about pre-IPO shares being available. Investor Wisdom Newsletter for Q1 FY2018-19 is out !! – Alpha Ideas
The other option is
These details apart, let us continue the discussion on RBL and its prospects.