"We are happy to share that we will unveil Jio to our colleagues first, on the eve of our founder chairman's (Dhirubhai Ambani) birth anniversary," Reliance Industries Chairman and Managing Director Mukesh Ambani with his wife Nita Ambani said in an invitation letter to employees.
Bollywood actor Shah Rukh Khan and musician A R Rahman will host the function on December 27.
"We want every member of our Reliance family to participate either in person or virtually through a Jio telecom beamed live to more than 1000 locations across India," Ambanis said in the letter.
There had been reports that RJio would launch its much-awaited commercial 4G services on December 28.
RIL CMD Mukesh Ambani in June had said that beta programme (trials) of Reliance Jio "will be upgraded into commercial operations around December of this (2015) year" and "financial year 2016-17 will be the first full year of commercial operations for Jio".
Later in October, RIL said financial year "2016-17 is projected to be the first year of commercial operations for RJIL".
Reliance Jio holds the highest amount of liberalised spectrum among telecom operators which can be used for deploying any technology for mobile services.
It has a total of 751.1 MHz spectrum across 800MHz, 1800MHz and 2300MHz bands.
According to field trials by brokerage firm Credit Suisse, download speed on 4G network of Reliance Jio during its beta-test phase peaked at 70mbps but remained in 15-30mbps range on most occasions.