Hello Rishabh
An organization could use a dozen languages accross their codebase, but that doesn't mean everyone needs to master all of them! More often than not, a single one would be enough to present a good proposal. The list of languages are most so that. If an organization needs someone to code in OCaml or Ruby and when presenting the proposals you only know to code .Net in C#, you should probably focus on a different org that uses a language that you can speak more fluently.
But, there is not a need to know all of the languages they use. You should focus in providing a strong proposal. For example, if this proposal is about some changes in an Angular frontend, you probably only need Javascript and CSS. On the other hand, if it was backend-related, you would probably not touch Javascript at all. Having some overall knowledge can't hurt, and there may be projects which could need a bit of multiple languages, but there is no need to know everything. Obviously, present a project which suits you. If you are strong in language X and weak in Y, you will probably be able to produce a better result in a X-based project than a Y-base one.
Also, understand at high level the organizations and how their projects are designed. A single well-developed proposal to an organization you have engaged with is more likely to suceed than multiple proposals about projects you barely understood.
Best regards