The procedure of retrenchment has been given under Section 25G of the Industrial Disputes Act. Section 25F of the Act provides mandatory conditions for retrenchment of workers. Any workman working in a firm for 240 days or more in the previous 12 months can in principle claim retrenchment compensation.
So Firstly you need to check whether you fall within the definition of 'workman' as given in Section 2(s) of the Industrial Disputes Act. If you fall within the same then you are entitled to claim retrenchment compensation.
You should send them a legal notice claiming retrenchment compensation within 30 days and if the same is not paid then, you can file a written complaint to the Labour Commissioner under whose jurisdiction your company falls claiming the non-payment of retrenchment compensation as the same shall fall within the definition of "Industrial Dispute".