Clarification on Additional Charges in Demand Letter for Greater Noida Project

Hi Everyone, I invested in a project in Greater Noida back in 2022. Recently, I received a final demand letter from the builder, which includes several additional charges that I am seeking clarification on. I would greatly appreciate the community’s insights on the validity of these charges. Here is a list of charges mentioned in the demand letter: 1. Cost Against ESS Charges (Cost of 6 KVA Mains Included) 2. Cost of Backup Charges (Total 5 KVA, inclusive of 1 KVA Free) 3. Water Charges 4. Sewerage Charges 5. Cost of IGL 6. Balcony Light (4 Nos.) 7. Fiber to Home 8. Labour Cess 9. Partikar (₹20/- per Sq. Ft. extra) 10. Solar System for Common Area Lights (₹15/- per Sq. Ft. extra) 11. Advance Maintenance for 24 Months @ ₹2.50 per Sq. Ft. per month Could someone guide me on: 1. Which of these charges are generally valid and mandatory as per applicable laws or regulations? 2. Are there any charges here that I could contest or negotiate with the builder? I look forward to your advice and suggestions. Thank you in advance!