Mumbai, Dec. 1: Reliance Jio is extending its free domestic data and voice call offer till March 31, 2017.

Mukesh Ambani, chairman of Reliance Industries, today announced Jio Happy New Year, which will offer free data, voice, video and applications till March 31 for subscribers joining from December 4.

The offer will also be applicable to existing customers who are part of the introductory Jio Welcome plan. These customers will enjoy similar benefits till December 31, following which they will be merged with the new offer.

However, the plan announced today will cap data allowance for Reliance Jio customers at around 1 GB per day.

According to Jio, 80 per cent of its subscribers use up to 1 GB of data daily, while the remaining 20 per cent use disproportionately more data. It has, therefore, limited the high-speed-data quantity to 1 GB per day per user, following which the speed will be reduced to 128 Kbps.

Subscribers who wish to consume additional data beyond 1GB per day will have to choose from various tariff options. This step, the company added, has been taken to ensure that all Jio users get superior data experience.

Under the current Trai norms, promotional offers cannot exceed a period of 90 days. Jio had commenced commercial operations on September 5.

When asked about the validity of Jio's offer, Trai chairman R.S. Sharma said: "We will look into it. Every tariff that is filed before us is examined. We will come up with our response at an appropriate time."

The regulator had earlier allowed Jio to provide free service till the end of this year for customers who subscribed to its services till December 3.

Fastest fifty

Unveiling the new offer today, Ambani said that in 83 days from launch, Jio has crossed 50 million subscribers and the average rate of addition of 6 lakh subscribers per day is the fastest achieved for any technology company in the world, including Facebook, WhatsApp and Skype.

Telecom stocks tumble

Stocks of major telecom companies tumbled as much as 6 per cent after RIL extended its offer till March 31. The Idea Cellular, Bharti Airtel and Reliance Communications scrips witnessed heavy selling pressure following the announcement.

Idea Cellular closed the day at Rs 72.95, down 5.93 per cent, while Bharti Airtel settled at Rs 319.10 - down 1.66 per cent. Reliance Communications closed at Rs 35.75, down 5.05 per cent.

Demonetisation drive

Ambani today threw his weight behind Prime Minister Narendra Modi's demonetisation move, saying in a single stroke all unproductive money has been brought into productive use.

Ambani said he wants to "congratulate and applaud" Modi for his "bold and historic decision".