Step 1: Understanding the question.
The question asks to identify the option that is not classified as a Union Territory of India.
Step 2: Analyzing the options.
(A) Chandigarh: Chandigarh is a Union Territory and serves as the capital of Punjab and Haryana.
(B) Assam: Correct — Assam is a state of India, not a Union Territory.
(C) Ladakh: Ladakh is a Union Territory formed in 2019.
(D) Puducherry: Puducherry is a Union Territory of India.
Step 3: Conclusion.
Assam is not a Union Territory of India.