It is very important to plan your job switch properly. Else you may lose many important documents in the process.
Here's the checklist to make things easy for you :
1) First, give your resignation on time properly via Email or official letter to your superior. You may have a notice period in your company which you need to complete before leaving the company.
2) Experience Letter and Relieving Letter.
3) Full and Final Settlement to confirm that you don't have any dues to & from the company.
4) You are eligible for Gratuity if you have completed continuous service of 5 years in this company.
5) Transfer of EPF/NPS accounts or Withdrawal of EPF.
6) Collect your Joining Letter, Appraisal Letter, at least 6 months of Salary slip and any other proof of achievement in this company.
7) If you have a Salary account associated with this company, then transfer it to New Company or close it. Else it will be converted to a Normal Savings account and you may need to maintain a minimum balance.
8) If you have Group Health Insurance with this company, then take an Individual Health Insurance from outside to get continuity Benefits. There are chances that your new company may also have Group Health Insurance.
9) Delete or Transfer Personal Data from your official laptop.
10) Talk to your colleagues or superiors for any future reference.