Can a single spin reach the maximum win?
Each spin lands on the reels at random, so the Free Spins round may arrive on the first spin or not at all in a session. No one can know in advance how often it comes. The result of one session is random whatever the RTP, because the RTP only describes the average over a very long run.
Every spin on the 6x5 grid runs at one RTP version, yet the grid never shows which one. Only the game rules name the version this site runs, so read them before you stake. Once you find it, the RTP figure becomes the long-run return you can compare against the other versions.
Tumbles and multipliers can stack on one spin, so a single round may climb far above its bet. The maximum win is a ceiling that is reached very rarely, and no session can be planned around it. Treat it as the top of the scale rather than a target.