I am using wifi connection (5Ghz band) for Jio STB. I get full 300 Mbps for both download and upload on NetVelocity speed test which is as per my plan speed.
Not just that, I've seen Amazon Prime as well as Netflix getting ads in Jio fiber while at friend's house. It's like purchasing low cost inferior equipment in bulk to reduce costs and serve same sht to common people so here Jio tiedup with ad pushed plans from these OTT players clubbing it into Jio fiber and served it