I did some research on TGE. But I didn't understand this clearly. What are the requirements you need to fulfill to get this token? Is gambling mandatory to get this Airdrop? And what are the requirements based on which the reward amount will increase?
You just need to sign up & play. By playing (wagering), you earn points... which count towards your share of the airdrop. Some casinos have presales for their tokens, but Reroll is all about wagering... And I find that more interesting.

You can check more about it here:
https://reroll.gg/pointsAnd in the future, will your native token be used only for playing casino games on the casino platform or will it be listed on the exchanger like the tokens of other casino platforms? Although the question is noob, I am waiting for a clear answer. sorry for the noob question
Well, I think it's too early to say anything about it. Crypto casino tokens have different paths, so we need to wait and see how things develop. You can check this thread to see how some other casinos do it:
https://bitcointalk.org/index.php?topic=5595716.msg67201114#msg67201114