You have to pass any degree level course in graduation level to become a collector in India .. it is completely depends on your interest to choose course at undergraduate degree . for the post of collector you have to pass Indian Administrative Service (IAS) Examination organized by UPSC ..

Exam pattern :
Scheme of CS (Preliminary) Examination
The Preliminary Examination consists of two papers of objective type (multiple-choice questions)

General Studies Paper - I 200 Marks
General Studies Paper - II 200 Marks

Scheme - CS (Main)
Paper-I
One of the Indian Languages to be selected by the candidate from the 18 languages included in the VIIIth Schedule to the Constitution (Qualifying Paper) 300 Marks
Paper-II English (Qualifying Paper) 300 Marks
Paper-III Essay 200 Marks
Papers IV & V General Studies (300 Marks for each paper) 600 Marks
Papers VI, VII, VIII & IX
Any two subjects (each having 2 papers) to be selected from the prescribed optional subjects (300 marks for each paper) 1200 Marks
Total Marks for Written Examination 2000 Marks
Interview Test 300 Marks
Grand Total 2300 Marks