Need advice on delayed possesion on private property

I had purchased a 1000sq ft flat in Pune, PCMC limit, in March 16. A registered sale deed and purchase agreement has been executed in Pune in April-16. I am the sole owner of the same. A Home Loan has been granted in June-16. Till date I have paid 65% of total amount. As per the agreement possession date was Dec-16, and till date the property is under construction and there has been a delay of more than 6 months as per the promises during sales and till date. I have been paying my EMI from July-16 onwards, I am now worried about delay in possession and no progress on development. I need suggestion, articles where clear consumer protection act clause are mention. Also, I would like to know, shall I wait for some more time or shall I go ahead and file a complaint in consumer court against the construction company. Thanks