In my opinion, your choice of RPA tool need not depend upon the programming language you know. Most RPA tools are designed such that they do not expect a RPA developer to know a lot of coding.
Having said that, it does help if you know a programming language like C#, .NET. or VB as the RPA tools allow custom coding to be done to stitch together a process flow. At those times, knowing one of the languages proves to be an advantage. But knowing a programming language is not a pre-requisite and not knowing one is not a constraint to build skills on a RPA tool.
Each RPA tool has it’s place in the market, you may want to build a good high level awareness about the capability differences of the leading ones, and of course go deeper in the ones that you then choose to.