Immigrant with criminal history

My nephew is an Indian citizen considering moving to the UK and I’m trying to understand what realistic immigration options might exist for him.

He is a practicing Sikh, speaks English, and has some experience in tech/development work, but he does not have a university degree. The major complication is that he has 5 sexual assault charges from India including an incident with a minor under 13. I’m not sure how UK immigration authorities view pending charges vs convictions, or whether this would make him automatically inadmissible.

We are not looking for ways to hide anything we are just trying to understand realistically:

\- Would the UK deny entry automatically for this kind of background?
\- Is there a difference between pending charges and convictions?
\- Would any visa routes still be possible without a degree?
\- Are there legal pathways through work, asylum, religious/community sponsorship, marriage, etc.?
\- Would hiring an immigration solicitor even be worthwhile in this situation?

Looking for honest answers from people familiar with UK immigration law or criminal inadmissibility rules.rules.