The maximum number of bots is subjective because, as for the number of props, it's based on the capacity of the graphics card of your pc.
However, consider that they are nothing more than avatars, so for each bot you add to your layout, reduce the maximum capacity of users in your property.
The lag effect is sometimes mitigated by the personal setting of the game regarding the maximum avatars that can be viewed, in fact even the bots and/or avatars exceeding this number are not visible, but it should not be forgotten that even if hidden, they affect the load on the computer memory.
Having said that, the answer to your question should be: although theoretically there is no limit to the number of bots, in reality this value is the difference between the number of guests you would like in your place and the maximum number of users allowed in your property and therefore is advisable to use very few of them.