Advise for job switch preparation

I'm a 6 years experienced Ruby on Rails developer. Although I'm a little better than average, the problem of that I dunno a lot besides Rails.

I'm stuck at around 12 LPA. The job is good, I'm working with one of the major US public organizations and it's permanent WFH.

But at this point in my career, 12 LPA feels very miserable and the interviews for 6 years experienced demands a lot.

Any advices on how and what should I prepare? Any good companies with reasonable demands on Rails dev positions?