Ok it’s solved. I just called up the web hosting providers. The guy asked me to do one thing and it fixed a dozen problems.
He told me to go to File Lock and Unlock it. I did that and then I was able to remove/delete plugins from cPanel. I renamed a plugin and ow I can install new plugins as well.
Hell, I have been slogging it out from past 7 hrs, if only I would have called them up in the first place!