Though government is considering tightening noose around n*d*ty or sexual content available on internet but nothing has been formalised till now.
The main reason for blocking p**n Sites by Jio would most likely be to reduce data consumption. Maximum usage of data is for watching such content. Jio is offering data free or at very low price, now that they have acquired huge customer base their goal will shift to increase revenue + achieve max profit. If they simply raise plan charges or reduce benefits then there will be backlash from customers hence this is an easy way to attain objective thru alternate route. If less data is availed by Jio users then operator margin will automatically improve
As i always say if u delve deep the real truth behind the story emerges