TDS on salary

you will have to calculate the total tax payable on the annual salary , if it exceeds the basic exemption limit at the applicable slab rates and on the basis of that you will deduct the TDS amount on salary

 

Calculate the total taxable salary of the year. Deduct the eligible investment under Chapter VI A, then deduct home loan interest if applicable. On the balance calculate the tax payable and divide it with number of months to go till the March. This shud be deducted monthly from the salary paid each month.
If you receive fresh investment from employee then again recalculate the tax liability and deduct tax accordingly