As you have asked about the courses to do after the third year B.Com

Master degree Course After Completing B.com Course ::

M.COM ( Master of Commerce )
M.ECO ( Master of Economics )
M.STAT( Master of Statistics )
M.A ( Master of Arts )
B.ED Bachelor of Education
MA in MASTERS IN FINANCIAL ANALYSTS
MA in MASS COMMUNICATION

Comptitive Examination After B.com Course ::

Civil Service Examination
Banking Service Examination
Defence Service Examination
Insurace Service Examination

Professional Courses ::

ICAI Institute of Chartered Accountant of India
ICSI Institute of Company Secretary of India
ICFAI Institute of Chartered Financial Analyst
ICWAI Institute of Cost and Work Accountant of India