From Thursday, more than 30% of the city's cable households, that have not switched to set-top boxes, are expected to only see black squiggles on their television sets. Officials have, however, claimed a near-complete digitisation in the city.
After the Bombay high court refused to extend the October 31 deadline, cable operator associations said they would approach the Supreme Court.
The Cable Operators Federation of India (COFI) estimated a 60-65% digitisation success in the city, while several cable operators and associations claimed 75% digitisation had been done till Wednesday. There are about 30 lakh households with TV sets in the city.
"It is hard to believe official figures of 100% digitisation," said Roop Sharma, president, COFI.
"More time is needed to ensure smooth and complete digitisation without forcing technology on customers," Sharma said.
"Around 30% households will be affected from Thursday with the expiration of the deadline," said Anil Parab, president of the Cable Operators Association.
Several cable operators cited chaos over the last few days before the deadline.
"There has been no uniformity in set-top box charges, with some subscribers charged more than Rs 1,500, though the standard price is about Rs800," said Vishwanath Girkar, president, Mumbai Cable Network Owners' Association.
"Cable operators are planning to protest in the next few days to get the deadline extended till after Diwali," he said.
Cable broadcasters received a flood of digitisation demands in the days leading to the deadline.
"Over the last week alone, we have made as many as 90,000 digitisation switchovers in the city," said Madhav Betgeri from InCablenet, one of the seven multiple-service operators (MSOs) in the city.
DTH companies forecast a huge surge in demand for set-top boxes from Thursday.
"We have already seen a seven-fold increase in demand for set-top boxes in the city," said Salil Kapoor, chief operating officer, Dish TV.
"We are now expecting a further increase from Thursday, though it will take time to service these demands as we are falling short of staff for installation," he said.
Customers were still hopeful of an extension in the deadline. "I have been trying to contact several DTH companies for a set-top box, but they haven't responded," said Sandy Taneja, a Malad resident, who will not be able to watch television from Thursday.
"I hope that we get more time to make the switch, but if there's no extension, I will use the Internet to watch programmes for the time being," Taneja said.