Additional District Sessions Judge Raj Bahadur also imposed a fine of Rs 5,000 each on the accused Shankar, Jashod, Ravi, Pradeep, Sunil and Ashok.
Another accused Lallan was acquitted by the court due to lack of evidences.
Revati Singh, 75, wife of the BJP leader in Uttar Pradesh Assembly, was murdered and Rs 78 lakh in cash and ornaments were looted from their house here on July 30, 2010.
Police had later arrested seven persons, including domestic help Shankar, and recovered Rs 52.80 lakh from them.