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.