RERA promises vs. my reality after moving in

Whitefield, just moved into Prestige City last month. Honestly, OC ke bina possession de diya, and now society formation mein bhi delays chal rahe hain. Everyone talks about RERA, but my experience says it's mostly on paper, yaar. Builder delays ke against real legal options kya hain? Should I file a RERA complaint? Is it actually effective ya bas ek aur formality hai? Feel like things nobody told me before buying. Change my mind.