With a GATE 2023 Mechanical score of 450 and 38 marks, your chances of securing a job in a PSU are relatively slim, as most PSUs tend to have higher cutoff scores. However, some smaller or less competitive PSUs may still consider you for recruitment. It's also important to keep an eye on specific PSU requirements and openings. Additionally, you can explore opportunities in the private sector or consider reappearing for GATE to improve your score for better chances.

For more details you can visit the link given below

https://engineering.careers360.com/articles/gate-marks-vs-rank