Patel Group delay in Sector 48 - anyone else facing?

6 months past the promised possession date for my flat in Sector 48, Patel Group ka project hai. Honestly, I'm stressed. Paid almost 90% of the amount, and still no sign. My parents keep saying under-construction projects are always risky. Ab samajh nahi aa raha what to do. Should I complain to RERA? Anyone else facing similar delays with Patel Group? Or any advice on what steps I should take? Darr lag raha hai.