Forced resignation

On first week of October 2015 my company forcefully taken resignation of 7 employees including me. They called individuals into a room and threaten that if you are not resigning then we will terminate you by paying just 1 month notice period salary as per appointment letter. if you resign we will pay 1month pay for each completed year. Even though I argued and negotiated they were not agreeing anything. Also they were not allowed me to call any one or come out of room with out a decision. I do not had any option other than resign. Then they asked me to sign on an agreement that says I resigned myself and I will get 1 month pay for each completed year. They also taken my signature on a confirmation letter in which it is mentioned that I received the final settlement and I will not sue the company. All the 3 documents have same date. I didn't get the settlement amount till now. When I asked to HR, he told that it will come within a month. I think the dates on 3 papers - agreement, resignation and confirmation of receipt proves that my case is forced resignation. Also, the condition like I will not sue the company for unjust termination or compensation etc. shows that this is unusual case. Also, they taken my signature on confirmation about settlement received on same day, but it is delayed more than 1 month. All these shows that the resignation is not voluntary. Van I file a case and get back my job. I am now at 43 yrs old and I have 7 yrs service in that company. They are not even reafy to compute tax on compensation basis. They are computing the amount on "profit in lieu of salary" Is there any chance to sue the company on forceful resignation. At least I will get IT exemption if I prove it.