As I write this blog post this evening of 30th March, Reliance Jio announced that the existing prime members will continue to enjoy same benefits at no extra cost for another year, i.e. upto 31st March 2019. However, Reliance Jio has also stated that it is a limited time offer and subscribers will be required to "express interest" via "My Jio" app.
New subscribers, joining in to Reliance Jio on and from 1st April will have to enrol for Prime Membership club with a fee of ₹99 only.
There's no change in the tariff chart as of now. Reliance Jio also happens to be India's first prepaid auto-recharge. That can be done through credit/debit card or even directly authorising via bank account.
I'd not recommend auto-recharge of prepaid because when tariff plans change, there would be a big hassle cancelling the existing authorisation and opting for the revised tariff. Also, it takes away your freedom to choose any plan any month.