Delhi property negotiation is mostly a myth

Landlord just hiked rent again, I'm done. Finally looking to buy a 2BHK in Deep Vihar, maybe Arya Group ka project. Yaar, prices ₹1.5Cr tak jaa rahe hain. Kya negotiation Delhi mein work karta hai? Builders like Arya Group kitna discount dete hain? Possession ke time kya hidden charges aate hain? Heard about PLC, OC... not sure what all. Any experiences?