What compelled you to prepare fake relieving letter ? After 8 months of service why didn't you get relieved properly ? What you did is forgery. Please don't do this in future. It would be better to share your future employer that you don't have relieving letter rather presenting false relieving letter.
Talk to your ex-employer and try to solve it amicably. If your ex-employer communicate to your new company about fake certificate, maximum you may not get that employment. Otherwise I don't think ex-employer pursue on this legally even though they can. So try to close else leave it.
26th August 2019 From India, Madras