Plan your session around what is known
6x5 is the grid, but the grid does not say when a bonus comes. How often the free spins arrive is not known in advance, and the result of one session is random whatever the RTP. A figure such as 96.52 percent describes the return over a very large number of spins, not the outcome of the next one.
96.49, 96.50, 96.51 and 96.52 percent are the four RTP versions of Sweet Bonanza 2500, and only the game rules show which one is running. Each version sets a different long-run return, so the gap between them is small but real. Read the game rules before you start to see the version in use.
25,000 times the bet is the maximum win of Sweet Bonanza 2500, and it is reached very rarely. Treat that ceiling as a limit on paper, not a goal for any single session, and set your budget before you start.