every company has salary Policy
as BASIC VDA,DA.CONVEYANCE,COMPUTER AND MANY MORE ALLOWANCE WHICH IS PAID BY COMPANY NORMS AND ALSO DEDUCTION You can search through their respective attendance register and verifying their salary slip it is made as per their attendance you must verified their employee ID, which is provide by your company, so that you may be less stress to find out the fake payslip
Best of Luck
Regard
Santosh kumar Sinha
CCL,Ranchi (Jharkhand)