yes, you ARE eligible for home state quota at NIT Delhi even with 12th from Chandigarh. this is one of those things most people get wrong!
here's why: Chandigarh is a Union Territory, not a state. Union Territories don't have their own NITs. as per JoSAA rules, Chandigarh UT students are clubbed with NIT Delhi for the home state (HS) quota. NIT Delhi's HS seats are reserved for students from Delhi AND Chandigarh combined.
what this means practically:
just make sure your JoSAA profile correctly shows Chandigarh as your class 12 board location. if you've studied 11 + 12 in Chandigarh from a Chandigarh school, you're good. if you moved to Chandigarh only for class 12 from another state, double-check the residency requirements.
Yes, you will be eligible for Home State Quota in NIT Delhi Even if you have completed 12 from Chandigarh. Many people still believe that you can get a home Quota only in your state. The truth is these rules apply to States and not to territories. Chandigarh being a union territory is exempted from this rule.
Hope this helps you!