That has been visible in Mumbai for years now and will mostly stay visible till Rcom has the 2100 MHz spectrum in its possession. Which is either till 2030 or earlier if the insolvency proceeding concludes.
No, Jio users can't latch on to it. It's only for their very limited enterprise segment corporate users. The subscriber figures are still reported to TRAI every month, you can find it in the TRAI subscription report.