Response

The moment you have resigned from your post on any proper ground you are free to apply for any other post in or out of the company or organization for any other job. You are not required to submit any rule or regulation copy as a proof or to substantiate you up resignation and thereafter rejoining on a different position.

No, not in general given that PSUs typically hire straight from colleges or through special exams. But then, there could be a special recruitment drive for some specialists or you might apply for one of the executive posts if advertised. In the normal course, no.
Is it a hassle to resign, no, not unless you did something incredibly stupid or pissed someone who matters serious enough. However, being a PSU, you can still get out clean with all due benefits and always seek the court of law if you are wronged.

The best part about a PSU though is that, they will track you and even if slightly delayed, they will not forget to transfer you bonus, salary arrears, etc., Even multiple years after you have quit. Happened with me, after I quit from BPCL! And my resignation was fairly smooth, if it matters.
The resignation will be treated as technical resignation if these conditions are met, even if the Government Servant has not mentioned the word ÔTechnicalÕ while submitting his resignation.

The benefit of past service, if otherwise admissible under rules, may be given in such cases. Resignation in other cases including where competent authority has not allowed the Government servant to forward the application through proper channel will not be treated as a technical resignation and benefit of past service will not be admissible. Also, no question of benefit of a resignation being treated as a technical resignation arises in case of it being from a post held on ad-hoc basis.

Reference: No Particular law

2021001812021004112228

LAWAYZ-2023-132