ISD facility and international messaging will be available on chargeable basis shortly. You will be able to purchase the ISD voucher from MyJio app or by logging in to www.jio.com. Similarly packs will be available for international roaming shortly.
Is ISD facility and international roaming available on the Jio Welcome Offer? | Reliance Jio FAQs
So they have officially launched but do not support international roaming or ISD calls? Cool.