As you have asked about the Rajasthan Board of Secondary Education (RBSE) 12th class board exam date sheet, I am providing you with it
I want to tell you that the RBSE 12th class board exam has been already done.
So I am giving you information only for reference;

Day
Date
Time
Subject

Thursday
Mar 12, 2015
08:30 to 11:45 am
English (Mandatory)

Friday
Mar 13, 2015
08:30 to 11:45 am
Hindi (Mandatory)

Saturday
Mar 14, 2015
08:30 to 11:45 am
Computer Science, Informatics Practice, Multimedia Webtech

Monday
Mar 16, 2015
08:30 to 11:45 am
Accountancy, Political Science, Geology, Agriculture

Tuesday
Mar 17, 2015
08:30 to 11:45 am
Social Science

Wednesday Mar 18, 2015
08:30 to 11:45 am
Business Studies, Physics, History

Thursday
Mar 19, 2015
08:30 to 11:45 am
Vocals/Instrumental music [ (Tabla), (Pakhawaj), (Sitar), (Sarod), (Violin), (Dilruba), (Bansuri), (Guitar)]

Friday
Mar 20, 2015
08:30 to 11:45 am
Public Administration

Monday
Mar 23, 2015
08:30 to 11:45 am
English Literature

Tuesday
Mar 24, 2015
08:30 to 11:45 am
Maths
09:00 to 11:45 am Typing script (Hindi)

Wednesday
Mar 25, 2015
08:30 to 11:45 am
Philosophy

Thursday
Mar 26, 2015
08:30 to 11:45 am
Biology
Hindi Literature
Urdu Literature
Sindhi Literature
Gujarati Literature
Punjabi Literature
Rajasthani Literature
Farsi Literature
Prakrit Language
09:00 to 11:45 am Typing script (English)

Friday
Mar 27, 2015
08:30 to 11:45 am
Psychology

Monday
Mar 30, 2015
08:30 to 11:45 am
Sanskrit Literature

Tuesday
Mar 31, 2015
08:30 to 11:45 am
Economics, Chemistry, Shirg script- Hindi/ English

Wednesday
Apr 1, 2015
08:30 to 11:45 am
Home Science

Saturday
Apr 4, 2015
08:30 to 11:45 am
Drawing

Monday
Apr 6, 2015
08:30 to 11:45 am
Geography