People who are from or are native to Bangalore, India. Usually applies to techies, students, and others who have lived and worked in the city, not professionals who have been transferred there for a short time (i.e. a year).
Bangaloreans needn't be native to the state (Karnataka), native to southern India or ethnically Indian at all.
Bangaloreans are generally laidback and easy-going, affluent and pretty friendly, and are considered to be among the most cosmopolitan people in southern India. Some are apt to use Indian slang (1.), especially from South Indian languages. Many young Bangaloreans also enjoy eating out a late night dhabas (roadside food stalls, of a sort), which usually serves professionals/college students working late or people leaving nightclubs but reluctant to go straight home.
1. So what's your problem, yaar?
2. A: "So you ate at Empire last night?"
B: "Yeah man, I'm a pukka Bangalorean!"