I know a great school in Granada, it is called don Quijote. You can read about it here:
http://www.donquijote.org/ext/agi/xohpwfyv_rd.asp?url=/english/granada.asp
And sign up here:
http://www.donquijote.org/ext/agi/xohpwfyv_ln.asp
Really good school that can adapt to all your needs and a wide range of accommodation options to get you though the year.
I would reccomend the student visa. In order to get it, you will have to already enrolled in an academy who will they send you a letter of “invitation” which you will need in order to get a student visa.
Regarding your work, if your company is based out of India, and pays you out of India, and has no branch in Europe, then you effectively work for and only for India. If they allow you freedom of movement, then you may physically be in Spain but you still only work for India. This would change if your company had any branch or legal entity in Europe…
Good luck, we hope to see you soon!