Apartment not finished

Dear Forum, We (Hus and wife) bought and registered an apartment in Bangalore in 2007. However the builder did not finish the project and later the land owner cancelled the power of attorney of the builder and took over the project. Finally the buyers formed an association and made an agreement with land owner which is payment of 400/ sq. ft. for completing and getting out of ARCIL which was later increased to 650/sq. ft., because again the money was wasted by another builder. No it seems certain buyers go their apartment complete according to their msgs in a whats app group created by the assocn. and claiming that whoever gives money b4 december 2018 will get their flat completed. The issues are they are asking 750/sq.ft now 11 extra (penalty) for not paying in 2017 (all this started in 2014-15) and there is no assurance of whether we can get the apartment even if we pay. The land owners (agreed by assocn.) statement is such that if 80% of the buyers (land owner owns few flats and he has paid it seems, we are not sure) pay he will complete the apartments of those who paid it seems. Otherwise he won't (irrepective of we paying). this is the only assurance. We have no idea what to do. We have moved to thiruvananthapuram , hence cannot monitor the progress as well. Any insight into this problem will be appreciated. What are our rights. How to solve this. We are ready to pay (by loan). however not the penalty. and also needs an assurance. How to reach this. Sajeev kumar K.