The Arab nation accused all the individuals of gathering information about the submarine programme and sharing it with the Israeli secret services.
New Delhi said they were shocked to hear about the verdict and will follow the issue seriously with Qatar.
Suspects Were Ex-Navy Officers
All the suspects involved in espionage were ex-Indian Naval officers, the Financial Times reported.
The report said that the Qatari government arrested the suspects last year in August but the issue was not disclosed to the extent.
The death sentence sent shockwaves to India as the Indian Ministry of Foreign Affairs said that New Delhi was keen to follow up.
No Response From Israel
Meanwhile, the Israeli government has not responded to the news.
The verdict can put good relations between the two friendly countries on fire amid bitter situations in the Middle East.
Qatar being the largest supplier of LNG, can seriously damage the good business relationship with New Delhi.