First of all, if you are a 'workman' then only labor law, i.e., the Industrial Disputes Act, is applicable. In order to know whether you are a workman or not, the nature of your work is required.
Depending on the tenure of service with the company as well as the nature of the company, different labor laws may be applicable to you, and you may be entitled to more than 90 days' salary. Please note that there is no term as "asked to leave" under labor law. Either you resign voluntarily or the company terminates you. Since you have resigned voluntarily in this case (as you seem to have no documents to show that the company actually asked you to leave), you will be mostly guided by the terms and conditions of your appointment letter, which need to be looked into before further advice.