I'm sorry but can you please expand on your question a bit....
what exactly do you mean by "any companies run under linux platform?"
are you asking if the companies use linux for their internal infrastructure? do they develop and run their websites under linux? do they use linux for workstations? the question could mean a lot of things and its very hard to know what the companies run internally unless someone works there. As a loose generalisation, a lot of companies "use" linux in some way...