Gambhir has replaced Maheish Girri as the party's candidate and will take on Arvinder Singh Lovely of the Congress and Atishi of the Aam Aadmi Party.
Dikshit will take on BJP's sitting MP Manoj Tiwari and Aam Aadmi Party's Dilip Pandey.
Delhi has emerged as the youngest assembly in terms of age of elected legislators from the four states, with an estimated average age of about 43 years for members of Legislative Assembly elected in the national capital.