If builder has obtained the Commencement Certificate at the time of laying of foundation in the said project, then you can be rest assured that the builder will provide Occupancy Certificate on completion of the construction in the said project.
In addition to the builder mentioning it in the sale and construction agreements, you can take an undertaking from the builder on his office letter head as well, signed only by the builder and not his authorized signatory or a third person.
If you want to ascertain if the property you are buying is A Katha then you will need to visit an advocate office in Bangalore to get the same validated.