Hi you can recover your dues through summary suit in district court under Order 37 Civil Procedure Code (CPC).
In case the amount due to your is 3 lakhs and more in total then you can also file an insolvency petition in NCLT against the employer.
Sir based on the documentary proof and the claim amount you have we can go for a IBC proceedings against the company . The above is the best mode and you will be able to get a speedy remedy. However, you can also file a recovery suit against the Company for recovery of dues/ leave encashments/ arrears/ expenses. For claim for gratuity, if any, a proceedings before the gratuity officer will have to be initiated.
You may get issue a legal notice and then file a suit for recovery of arrears of salary.