I saw the ingame clan message that was querying for interest in the Clan Battles, which Season 7 has just started: https://worldofwarships.com/en/news/general-news/cvc-7/
I see that for Season 7 the days that Clan Battle sessions are running are:
Gaming sessions are available on: Wednesday, Thursday, Saturday, and Sunday.
After the World Series ends, I’m normally available on all of those days, and for the 4-hour block that Clan Battles are running. I mainly play the PvE Co-op Battle mode, so my PvP skills are weak and will be glad to step aside for a more proficient OTG’er.
I don’t have any Tier X ships of my own, but I have unlocked the “rental” Tier X ships that Wargaming provides. I would feel most comfortable in a cruiser, personally.