Article 159 of CoI : Article 159: Oath or affirmation by the Governor.

Explanation using Example

Example 1:

Mr. Rajesh Sharma has been appointed as the new Governor of the state of Maharashtra. Before he can officially start his duties, he must take an oath of office. On the appointed day, Mr. Sharma goes to the High Court of Bombay. The Chief Justice of the High Court is present to administer the oath. Mr. Sharma stands before the Chief Justice and recites the following oath:

"I, Rajesh Sharma, do swear in the name of God that I will faithfully execute the office of Governor of Maharashtra and will to the best of my ability preserve, protect and defend the Constitution and the law and that I will devote myself to the service and well-being of the people of Maharashtra."

After taking the oath, Mr. Sharma signs the oath document, officially marking the beginning of his term as Governor.

Example 2:

Ms. Priya Verma has been appointed as the acting Governor of the state of Karnataka due to the sudden resignation of the previous Governor. Before she can assume her responsibilities, she must take an oath of office. The Chief Justice of the Karnataka High Court is unavailable on the scheduled day, so the senior-most Judge of the High Court steps in to administer the oath. Ms. Verma stands before the senior-most Judge and recites the following oath:

"I, Priya Verma, do swear in the name of God that I will faithfully discharge the functions of the Governor of Karnataka and will to the best of my ability preserve, protect and defend the Constitution and the law and that I will devote myself to the service and well-being of the people of Karnataka."

After taking the oath, Ms. Verma signs the oath document, officially allowing her to start her duties as the acting Governor.