There are 26 letters used on the alphabet for the generation of the id. Since they can be upper or lower case there are 52 different letters shapes to be used. It is also used 10 numbers (0123456789) and the symbols "+" and "/". Therefore for every part of the id there are 64 possible symbols to be randomly assigned.
The probability of a kot appearing, based only on the previous information, is 2/64*2/64*2/64 since for every letter of kot there are 2 chances it will be chosen and letters can repeat (upper or lowercase). But there 6 possible locations kot may appear on the id since the id is formed of 8 different symbols, as you can see on the following:
Consequently, the probability of getting a kot id is (2/64*2/64*2/64)*6 which is 0.0001831055.
The total number os chances all anons have to get a kot id is simply given by removing the numerical possibilities of different symbols out of the previous equation, giving us 2*2*2*6 which is 48. Considering yesterday someone got a kot id and 6 other kot ids have been recorded before, there are still 41 chances for an anon to get the kot id.