Step 1: Historical fact.
The Reserve Bank of India (RBI) was established on 1st April 1935 under the Reserve Bank of India Act, 1934.
Step 2: Analyzing the options.
(A) 1935 – Correct.
(B) 1949 – Incorrect, this is when RBI was nationalized.
(C) 1401 – Incorrect, irrelevant year.
(D) 1619 – Incorrect.
Step 3: Conclusion.
Therefore, RBI was established in the year 1935.