Complaint against builder

Hello sir, 3 years before I was working as a property consultant, that time I sold some office spaces to some of my clients after clearing every term and without any hidden charges but even after 3 years builder is not constructing property and client wants to put case against him. I want to know certain things? 1) since last 2.5 years I am working in central excise and next week going to join income tax department with technical resignation, can that client put case against me as well because I received commission though from builder side and nothing from client? 2) real estate bill, norms will be applied now for a property sold before 3 years? 3) in case of FIR against me what are my grounds to save my job other than anticipatory bail? 4) can I file case against builder? 5) police verification needed in case of technical resignation? 6) mere filling FIR hamper my career? Please clear my doubts thnx a lot in advance ....