how much percentage is required to appear for cmat? as I am from a commerce background.

You can apply for the same reason even a Final year students of Bachelor's programmes are also eligible to apply. But you get a seat after qualifying exam with good score only. To do MBA , You must have 50% marks in graduation (any stream). Apart from this you need to clear any national level entrance exam such as CAT/ MAT/ XAT/ LPUNEST/ NMAT/ CMAT/ GMAT. Many colleges offer this course in India with different specializations. A few of them are:

Oil and Gas Management
Hospital and Healthcare Management,
Supply Chain and Logistics,
Tourism and Hospitality,
Financial Markets,
Finance,
Marketing,
Human Resources,
Business ,Operations,
Information Technology,
Retail Management,
Strategy,
Entrepreneurship,
Business Analytics,
E-Commerce,
Banking and Financial Services,
Agri - Business Management.

There are a few good colleges which offers dual specialization. The best B-schools are:

Shailesh J. Mehta School

Xavier's Labour Relations Institute, Jamshedpur

Lovely Professional University, Punjab

Department of Management Studies, IIT Delhi

Indian Institute of Foreign Trade, Delhi (own test)

Management Development Institute (MDI), Gurgaon

Bharathidasan Institute of Management(BIM), Trichy

Narsee Monjee Institute of Management Studies, Mumbai

National Institute of Industrial Engineering (NITIE), Mumbai

You require minimum 50% in your graduation as a General & OBC category & 45% as a reserved category to apply for CMAT entrance exam. To check complete information you can go through with given below link.

CMAT Eligibility

Good Luck!