What is more better to go for MBA or CPA for a student in 3rd year of graduation?

The only way an MBA can beat a CA is if he/she is from the top 15 universities - IIM ABCLKIS, SP Jain, FMS, JBIMS, MDI, etc.

Well, the basic differences between a CA and an MBA are -

1. Getting in - Any Tom, Dick and Harry can become an MBA. However, its really difficult to get in a top B-school. CAT is a scathing exam which really tests your aptitude. Anybody can enter the CA course. However, only a chosen few exit.
2. Focus on Communication - CA may be one of the toughest courses, however it lacks focus on communication. You see various CAs unable to converse in basic English. A 14-day GMCS is just not enough. MBA is different. With the focus on presentations and English being an integral part of the CAT, its more or less assured that the candidate knows the primary language in which business takes place in India.
3. Classroom Interaction - Many CAs get their graduation done through correspondence or through colleges with hardly any attendance norms. MBA changes that. Classroom intercation is stresse on and people learn how to work in teams.
4. Payment - An MBA from the top 10 institutes pays higher. Average package for a CA is 6–7 lac. Average package for top 10 colleges is 15–18 lacs.
5. A CA knows how to do the work. An MBA knows how to get the work done. I guess this is the fundamental difference.

In this competitive age, rather than asking CA v/s MBA, the best option would be to do CA AND MBA. This is the creamiest combination possible as far as finance and consulting jobs are concerned.

Hope you got the answer you are looking for thank-you.