Should I switch or stay

So, recently I got an offer from a start up company (11+1 lpa) it's a very small poker game developing company. Got referred by my dad's friend who is the founder.

My current CTC is 7.5LPA and I'll be getting a retention bonus of 70k if I stay till August.

If I join the startup in one month I will get a joining bonus of 60k, but my project won't release me that early. What is the best thing to do as of now