How to get salary details of wife from pan card

Getting PAN number is not difficult, but getting income details is difficult unless she was a govt employee where one can file RTI

You need to prove her present income and in absence of that her previous inncome.

If you are not sure if she is working at some company, you can hire detectives to find the same.

Allow her to state her present employment status in court under oath and if you are able to prove that she has lied, the court will take a very negative view on the same.  they will be convinced that she is trying to extort using legal means and may not get anything

If she is not working and was working earlier and know the company name, you can claim that she resigned from her job to claim maintenance.  Ask court to order her Form 16, bank statement etc.

Getting Income Tax details or TDS details is difficult, unless you know somebody from Income Tax Office.