Ah, this question again.
Box Office India website currently has data from 1993.
They have been slowly adding 1991-92' release entries to their database over last 3-4 years, but they have not added any figures or verdicts to them yet. Only BOI knows when they will update the data further, but there has been some progress(albeit slow) in recent years to their credit.
Your best bet is to ask BOI directly: [email protected]