No mostly North Indians (Kashmir to Maha and Gujarat to Bengal) use "Hinglish" in Group even out side of India,while South Indians mostly Use Pure English to communicate in their Groups. this is one of the main reason why North Indians and Pakistanis from Eastern Regions mostly Stay To gather/ or in Group because they can Communicate with each other in both Hinglish and English.
it's like Punjabi,Sindhi vs Pushtun and Balouch divide in Pakistanis. Purely Cultural not Racial.
Honestly I don't Know, maybe because of their Cultural Difference ?