Mainly the development stage tenders where the deliverables are part of a product or as a whole is a product to be made/developed. Capital expenditures are for a fully proven product via different trials & assessment that are certified for the military use. Military equipment need the different clearance certificate esp for export anyway.
Aim of Idex like venture is to build the mil complex yes but due to huge collusion internally how and why public/market money would flow into defence sector that has a very seasonal/lumpy sort of business and Govt procedure for L1 L2 etc makes it almost non-competitive process by feeding own psu/existing preferred bidder chain once the developed tech is scaled into a product. As tech transfer the companies/dev partners get the documents, they have to scale that written tech manuals into the usable product for the mil forces. That process itself takes multiple years depending upon how complex & multi domain the system is, costs spiral out and yet no certainty of any perceived order, psu co can team up with a foreign jv and offer one item which invariably gets L2 L3 at least and beats with price benchmark. This is old game & in this environment pvt defence vendors can not thrive.
Right now they are **thinking** about letting pvt entities bid competitively alongside the usual suspects, that should tell you everything.
Issue lies with the Govt, it actually does not want a thriving mil complex, it just wants to expand its tax base and privatise the loss making entity so it becomes someone else's headache. mak no mistake, Govt has money, enough of it, but politicians will prefer votebank over national security.