False promise of CTC by employer and offered lesser amount

Currently i am working and recently my company released a tender for the outsourcing agency and in the tender it was cited that the salary for the faculty to be CTC 16000 but when i receive the appointment letter the CTC amount mention was Rs 12851, when i contact the agency they told that the tender releasing company had said to do the same and the amount mention in tender was not to be taken seriously.