What hidden charges actually hit you at possession?

Since January I've been shortlisting flats in Gurgaon, mostly 2BHKs around Dwarka Expressway or Golf Course Ext Road, budget max ₹1.8 Cr. I'm seeing projects from DLF, M3M, and Godrej. Honestly, everyone quotes 'all-inclusive' but I keep hearing about huge hidden charges at possession – things like PLC, EDC, IDC. My parents keep saying builders always add stuff. What's the real deal with these hidden costs, especially for M3M or Godrej projects? Also, how's their actual construction quality after a year or two? Any specific builders notorious for plaster cracks or seepage? Ab samajh nahi aa raha.