Yes you can get admission in three year LLB course after passing B com course with good marks .. here I am giving you information about eligibility criteria for admission in three year LLB course .

LLB course :
Duration : 3 year

Eligibility :
You have to passed graduation level degree course in any discipline and you must obtained 45% marks from a well recognized university .
For admission you have to pass an entrance examination organized by college administration ..

Three year LLB colleges are :
NLSIU, Bangalore
NALSAR University of Law , Hyderabad
NIKU, Bhopal
National Law University , Jodhpur
Campus Law Centre, Delhi University , Delhi
NUJS, Kolkata
Symbiosis Society’s Law College , Pune
ILS Law College , Pune
Government Law College , Mumbai
Amity Law School , Delhi