i tell you something I know...
in my area jio didn't lay any wiring. they did dig up the holes and to my knowledge they were the old reliance communication ofc which they dig up and then deployed the JioFiber on the poles connecting the end to those ofc.
So basically, Reliance Comm. had OFC in our area for years... but were inactive.
JioFiber team comes, dig those fiber out (to take out the end of the wire).... connected their over-the-pole wiring to that....
provided connection to houses using over-the-pole way.