How many coins do I get for joining?

2,000 for Instagram and 2,000 for YouTube, once each, plus a possible performance bonus.

GoCoins: Allocation

You get a one-time connection bonus of 2,000 coins for linking Instagram and 2,000 for linking YouTube, once each. On top of that, you may earn a performance bonus based on your recent video reach.

Since 1 Coin equals ₹1, the connection bonus alone is up to ₹4,000 of value toward stays for connecting both channels.