Visa requirement query for Indian postdoc applying in UK
tl;dr: Read the job description.

Details: The job you're applying to is advertised publicly, and as a part of a job description it is normally explicitly stated whether or not the particular University is willing to sponsor the visa application for the non-EU candidates. If unsure, ask the contact person or/and their HR department.

If the university invites only those having a right to work in the UK to apply, there is nothing you can do about it &mdash; find another position to apply.

If the university is willing to sponsor the work visa for a candidate, there is nothing you (and your PI) need to worry about &mdash; the process will be handled by their HR department. Just make sure you meet Tier2 visa requirements.

Note that there are certain conditions for the University to apply for a Tier2 visa. Normally, the position should be advertised for at least 1 month. Also, the University should be a Tier2 sponsor (check the list).