Hi, :D
You can get all the information on following websites:-
www.hrodc.com - PG diploma in OD
http:// ashdrige.org.uk - courses on OD
IIM Calcutta also provide OD Courses -The course attempts to diagnose organisational systems and develop an analytical approach to planned system wise organisational change. It views the organisation as an interlinked system of groups attempting to integrate the organisational objectives with the goals of the individuals working for it. Cases and research findings from Indian Organizations are analyzed in order to understand the interventions required for effective organisational change.
You can aslo visit their site:-http://www.iimcal.ac.in/admissions/default.asp
Regards
Shruti