PST file is an online storage file of MS Outlook and It allows the user to store their mailbox data file but this file got corrupted sometime due to innocuous activities of the user and sometimes by a natural disaster like a power failure. In order to get back the access of data, PST file needs to repair for that.
Here is a complete informative blog about repair PST file.

PST file can be repaired either by Inbox Repair Tool or by third-party PST Repair Tool.
Get the complete version of PST repair tool: https://www.datarecovo.com/outlook-pst-repair-tool.html