India: One Kolkata class destroyer and its supply ship.
Japan: One of its Akizuki destroyers. Coincidentally, this destroyer has the same pennant as the Xi Jing Ping's review ship on the parade: 117.
Russia: Task force led by the frigate Admiral Gorshkov is headed up from the South China Seas. This fleet came all the way from the Baltic Sea Fleet. A separate fleet from the Pacific Sea Fleet might also be headed on its way from its port visit in the Philippines, possibly rendezvous with the Baltic Sea Fleet task group as they head to Qingdao. The Russians will be in force. After the parade they have a scheduled joint sea exercise with the PLAN.
Tencent has made a VR compilation of CGs of the main combatants involved in the parade, you should be able to view it in VR by scanning the QR code. Meanwhile, take a look at the CG pictures prepared by Tencent