The new Pudu Raya is less complicated than the old terminal I frequented back in 1999. The specific counter selling tickets to Genting is located at level 3. Please pay only in Ringgit (RM), the currency of Malaysia.
Buses will depart on time to Resorts World Genting from KL Pudu Raya. To avoid complication, please buy 2-way transfers and the cable car rides. Please leave your luggage in Pudu Raya. At level 2 corner there are some places where you pay to keep big or small ones.
It is nice to have an afternoon tea there when it starts to chill a little.
Here is the official site