I am MBA in Marketing & Btech in CS, having 1.5 years of exp in sales but i want to change my line to functional consultant or Analyst, how?

Though you can change it, but for an analyst or a consultant, most of the companies wants people who are having some years of experience. As you don't have any at present, try and stick to the same job and gain some more experience and then try for an Analyst/ consultancy job.