Additional District Sessions judge Rajesh Bhardwaj also imposed a fine of Rs 8,000 each on the accused, including Minu Tyagi, wife of gangster Vicky Tyagi who was gunned down in a courtroom here in 2015.
The six accused were held guilty on Wednesday under sections 147 (rioting) and 302 (murder) of the Indian Penal Code.
According to prosecution lawyer Yogesh Sharma, Satish Tyagi was shot dead in the district on July 3, 2007.