Conditions being put by company should I resign or get terminated

My company did capacity reduction and told to Resign with 10 months sal. Or get terminated as per employment terms. The term mentions any party can terminate without notice, with or without 3 mnths pay but with reason. I resigned under protest recorded it and next day mailed management that resigned under duress and hence created dispute. Now should and can I sue employer since I want my job . back.what are the rules for employee reduction/mass redundancy. I think I am workmen. Have I done correct thing...? Company has paid all dues on time. On what basis I was selected or basis no information given. Just forced to select on the spot. What should I do?