Most pre-school franchises in Bangalore are run by individuals, house-wives etc in small spaces. Most of them aren't safe, because those buildings were not constructed originally for kids. In addition, they'll not having playgrounds. The quality of teachers in most franchises I've seen are really bad. Most of the pre-school franchises pay their staff Rs.8000 to Rs.10000. So you won't really get good qualified staff. The only advantage as I see in pre-schools is that they might be closer to your home
Schools on the other hand have better processes in recruiting more qualified staff, more space for your kids. The disadvantage might me, the school could be a bit far from your place.
Having had my kids going to both pre-schools & regular school nursery - I can easily say that regular schools are much better.
Yes, schools are run more professionally compared to pre-schools. Pre-schools don't even have any accreditation or regulating bodies.
Unless formal schools are really really far, preferably enroll your kids in them. Most pre-schools are just day-care facilities in my opinion. If that's what your looking for, then they're fine. Otherwise, from most perspectives formal schools are better.