In my knowledge "Best Institutes for correspondence BBA" have still not been classified...
But IGNOU is one of the most recognised... others are
Kurukshetra University Haryana Class XII 3 years
University of Calicut,
School of Distance Education,
Kozhikode Kerala
Class XII 3 years
Guru Ghasidas University,
Institute of Distance Education,
Bilaspur Madhya Pradesh
Class XII 3 years
Pondicherry University,
Directorate of Distance Education,
University Campus Pondicherry
Class XII 3 years
ZED Career Academy,
F-1/31,
Krishan Nagar Delhi
Class XII 3 years
Jain Vishva Bharti Institute,
Directorate of Distance Education,
Ladnun Rajasthan
Class XII 3 years
Annamalai University,
Annamalai Nagar Tamil Nadu
Class XII 3 years
Bharathisadan University,
Centre for Distance Education,
Tiruchirappalli Tamil Nadu
Class XII 3 years
University of Madras,
Institute of Correspondence Education,
Chepauk, Chennai Tamil Nadu
Class XII 3 years
JVBI,
Shati Niketan West Bengal
Class XII 3 years
Ajmal Mirza