Indian government (maybe other also) say that " to ban cryptocurrency we need global help" my question is : can bitcoin be banned if all government will agree to ban bitcoin
Well, they could theoretically force exchanges out of their countries, but that's about it. The decentralized P2P part of bitcoin, the nodes, cannot be banned. Even if some country does criminalize running a node, you can anonymize your traffic through the Tor network to evade detection.