There are some schools which teach NIOS syllabus in regular classes from 8th Standard onwards at BANGALORE.

Asha Kiran Special Need School (Integrated School), # 15, 7th Main, Indira Nagar 2nd Stage, Bangalore 560038. Tel: 25258159.
Deepika School (Integrated School), 28th Main, 35th Cross, Jayanagar 4th T Block, Bangalore 560011 Principal: Smt Seetha krishnamurthy, Tel: 26645767
Deepika School (Branch), #2805, 14th B Main, 8-E Cross, Attiguppe, Vijayanagar, Bangalore. Smt. Hema Nataraj Tel: 2339 3222
Poorna School, Opposite DPS Bangalore North, Sathnur Village, Bagalur Post, Jalla Hobli, Bangalore 49. Smt Indira Vijayasimha, Tel: 2279 2042
Parijma Learning Centre, BTS Depot Road, Wilson Garden, Bangalore 27. Ms Archana, Tel: 2223 8534, 2224 3634
Kensri School, Mariya Street, Mariyanna Palya, Bangalore 24, Tel: 2353 3528, 2353 7665
Larkspur House of Learning, # 3/4, Berlie Street Cross, Langford Town, Bangalore. Tel: 2272 7183, 98807 11736
Iyer High School, HMT Main Road, Mathikere, Bangalore 54. Tel; 23372714
Nehru Open School, St John’s Chrch Road, Bangalore 05. Tel: 2546 0531
Spastic Society of karnataka, # 31, 5th Cross, Off 5th Main, Indiranagar 1st Stage, Bangalore 38. Tel: 2528 1831, 2527 4633
Cluny Convent High School, 11th Main, 14th Cross, Malleshwaram, Bangalore 03.
Baldwins Girls High School, Richmond Circle, Bangalore

I hope these sort of schools to be available atleast in all the major cities.