I have a B.com degree from IGNOU and Senior Diploma in French from Osmania University.

I have a B.com degree from IGNOU and Senior Diploma in French from Osmania University. I have 2.5 years of experience as a technical writer. Am I eligible for a H1B visa? Please suggest some good evaluation agencies.

You need to have equivalent of 4 years of US Bachelors degree. So you should get education evaluation done for your degrees and marksheets to know the US equivalent of your education. If it is less than 4 years, then you need relevant work experience to make-up for the gap. You would need at least 3 years of relevant work experience for each missing year of education.