Some casinos offer players a casino bonus when they deposit, but it depends on your country of residence if you are eligible for a bonus. The best thing is to take a look at the casino directly to see if players from Georgia are eligible for a bonus.
If you are offered a bonus from the casino, and you've selected GEL for your account, you should also be able to claim the bonus with Lari, but keep in mind that if the bonus is shown in a different currency, the amount will be converted.