From the SC to GDR side, ongl (Ongole) is given a specific quota. The system first fills this quota and then allows further booking in the NLR (Nellore) combined quota. So, it appears like this... ideally, once the quota is full, it should assign RLWL (Remote Location Waiting List) instead of allocating seats in the NLR general quota. However, in the Indian Railways (IR) system, they do it differently. On the other hand, from the GDR to SC side, ongl is given a remote quota. The system first fills this quota and then allows RLWL. Since the quota is less than the demand from Ongole travelers, they have to book from Nellore by paying a higher fare if there are available seats. As ongl is given a remote location, the remaining demand is forced to book under Tatkal and Premium Tatkal, which now accounts for 30% of the total berths. Let me give you a specific example. The Cocanada Express from Kakinada (KKD) to Lalaguda (LPI) and Bhimavaram (BVRM) is given a remote quota of 61 seats in 3AC. According to the data analysis posted on May 9th, 144 seats are already booked in 3AC. So, once 61 seats are filled from Bhimavaram, it shows WL (Waiting List) if tickets are available from Tanuku. Otherwise, passengers have to opt for Tatkal booking. This means around 80 tickets should be booked under Tatkal from Bhimavaram to meet the demand-supply gap. This RL quota will increase the demand for Tatkal from intermediate stations and earn more revenue for the train.