Yes, you can appear in any Government recruitment examination (Central Government, State Government or PSU), during your study. However, you must remember that you should appear only in those examinations for which you are eligible on the date of publication of the advertisement. Generally, for Government recruitment examinations, a qualification which will be acquired in the future is not taken into consideration.
"If you are killed in action, you go to Heaven. If you win, you rule this Earth (as beautiful as Heaven). That is why, O son of Kunti, take a firm resolve and fight!"-- Shrimad Bhagwad Gita