BLR- How to proceed to get profitable refund from builder at fault of Construction delayed by years.

Please read patiently & advise. Along with a friend as partner as co-owner/ co-applicant, I purchased an apartment flat under construction (G+4 floors) having 500 + flats in that project. I received the Sale & Construction Agreement, & both have different values, for example, total cost of flat agreed b/w me & builder was 40 lakh, then, SA & CA has 25 & 15 lakh quotes. I read, as joint venture Builder owns 70% share of flats Approx 30% ratio is for landlords. Via cheque or govt. bank home loan, we had paid 95% of the value by 2015 end. 5% remaining due on possession / handover date Expected was Dec 2016 . Facts - 1. Builder took 95% of value from all buyers & revolved around with money & got himself into other deals. Later he started 3 more huge projects & new projects are RERA registered. 2. The builder says- BESCOM has not yet approved/provided with facility to give individual flats its own electricity Meters. There seems to be a conflict that substation is required & we dont know, who is responsible for substation( Builder or BESCOM). 3. The rest of the construction is still way too far from completion & expected by end of 2018. Problem - 1. A clause in agreement says that the builder bound to pay penalty of 4Rs. / Sq ft of flat super area, per month , for delay from original promised possession date. 2. We don't have completion date as Dec 2016 documented in agreement, it was only in advertisement online/marketing material. 3. The Project is not RERA registered. Issue - The project is being progressed at a very slow speed in phase /phase & block by block manner. Builder by email phone call is forcing customers to pay 5% & take handover of flat. Only wall work completed(floor tiles, painting , internal wiring/water/drainage connections etc are not done ) the internal road/club house/amenities are not been constructed yet. most importantly, No water or power current line for the project When people demanded to adjust the penalty, builder threatened the customers to cancel the flat & not refunding the money. Few have taken the possession, they were not compensated with the penalty despite delay. This took a strange U-Turn wherein the builder instead of pleading guilty, threatened the customer such as, builder will file case against the customer for act of defaming the builder or/& for extortion of money by power & to some even creating problem for life of their beloved ones & themselves. Builder claimed to have a backup in terms of power & money from political connections & claimed to have share of some politicians in his different projects to benefit from money launderind. & says have police backup & thugs/man power to cause disturbance in daily routine of life of any customer who say a word against him. None of us know if all the things that builder/employees told are true to their nature or he was just calling bluff to scare the people to be in a profit. Any advice?