Dear Sachin,
There is no mention of the nature of the job you resigned from, i.e., workman, supervisory, or managerial.
Gratuity Claim Process
Regarding gratuity, you should file a claim for gratuity with interest for the period of default, irrespective of the nature of the job, before the Controlling Authority under the Payment of Gratuity Act for the area of your previous job location. The claim must be based on the sum of basic and D.A payable in the last month of your service.
Unpaid Salary Claim
In relation to the last month's unpaid salary, if your salary does not exceed Rs. 24,000 per month, you can file a claim under Section 15(1) of the Payment of Wages Act, 1936, before the Deputy Labor Commissioner for the area where you last worked.
Workman Claim Options
If you were a workman, alternatively, you can file a claim under Section 33-C(1) of the Industrial Disputes Act, 1947, to the Secretary of the State Government's Labor Department.
Managerial Position Claim
In the case of having had a managerial nature of the job, you can institute a Civil Suit for breach of contract and claim damages.