The Press Trust of India news agency reported on Monday that Mohammed Arif, who police said is a member of the outlawed Pakistan-based Lashkar-e-Tayyaba group, was found guilty of waging war against India.
Two of Arif's Indian co-conspirators, Nazir Ahmed Qasid and his son Farooq Ahmad Qasid, received life sentences, PTI reported.
Police did not identify them as members of Lashkar-e-Tayyaba.
Lashkar-e-Tayyaba is one of dozens of separatist groups fighting against Indian forces in Indian-administered Kashmir. The group seeks Kashmir's merger with Pakistan.
It has been declared a terrorist group by India and the United States, and Pakistan's government says it is cracking down on the group.
Large crowds gathered outside the court ahead of the sentencing, calling for the maximum penalty, India's NDTV reported.
Arif's Indian wife, Rehmana Yousuf Farooqi, was found guilty on Monday of harbouring an offender, but was acquitted of the more serious charges of waging war against the country.
She received seven years in jail, PTI reported.
Another man who ran an internet cafe and helped Arif also received a seven-year sentence. Four others were acquitted.
The verdict was delivered amid high police security in the wake of the weekend bombings.