Hello Inderpal07,
Since you are a new member of this Forum, it's understandable that you may not know it.
Like N.K. Sundaram pointed-out, UNLESS you give ALL & COMPLETE facts right @ the beginning, you can only expect half-baked suggestions....that most likely WILL lead you or your friend to more trouble than a solution.
You mentioned "They say that client has done a complaint against him. But either complaint came in notice period or even if it came earlier, no action was initiated before notice period".
You YOURSELF aren't sure of this fact......IF you really wanted to help your friend [or for whichever purpose you posted this issue in this Forum], you could have checked-out the details & THEN posted them. Also 'Complaint' can mean anything.....to the one who is the 'target', it could mean atrocious, to the Company it could mean 'well-deserved' & to others like the members of this Forum, it could be quite something else UNLESS the details of WHAT the complaint was all about comes to the fore.
Hope you get the point.
This also leads one to another issue.....that's also not very common: "Valuing others' time as you would your's".
Rgds,
TS