@fuat2mb
Yes, Conversations can definitely do video calls (at least one-to-one), and @monocles is a fork of Conversations, so I guess that should work, too. If you're looking for a server that supports video calls, https://compliance.conversations.im/ might help you find one. I think XEP-0215 (discovery, particularly of STUN and TURN services) is the one you want for video calls. I'm not sure whether the clients can do video calls even without STUN or TURN if they have IPv6 addresses (for example, Yggdrasil addresses); that's something I haven't tested yet.
I think some clients, such as @dino, have some support for multi-party video calls, but that's another thing I haven't tried out yet.