The answer is : Though the question is somewhat vague, it can be answered by counting the number of times oath for the office of the Prime Minister had been taken.

1st - Nehru as the head of the government which took over from the British.

2nd - Nehru after 1952 General elections.

3rd - Nehru after 1957 General elections.

4th - Nehru after 1962 General elections.

5th - Gulzarilal Nanda (acting PM) after death of Nehru in 1964.

6th - Lal Bahadur SHASTRI in 1964.

7th - Gulzarilal Nanda (acting PM) after death of Shastri in 1966.

8th - Indira Gandhi in 1966.

9th - Indira Gandhi after 1967 General elections.

10th - Indira Gandhi after 1971 General elections.

11th - Morarji Desai after 1977 General elections.

12th - Charan Singh in 1979 after the fall of Morarji Desai's government.

13th - Indira Gandhi after 1980 General elections.

14th - Rajiv Gandhi in 1984 after assassination of Indira Gandhi.

15th - Rajiv Gandhi after 1984 General elections.

16th - Vishwanath Pratap Singh after 1989 General elections.

17th - Chandrashekhar Singh in 1990 after the fall of V. P. Singh’s government.

18th - P. V. Narsimha Rao after 1991 General elections.

16th - Atal Bihari VAJPAYEE after 1996 General elections.

17th - H. D. DEVE Gowda in 1996 after Vajpayee could not garner majority.

18th - Inder Kumar Gujral in 1997 after the fall of Deve Gowda's government.

19th - Atal Bihari Vajpayee after 1998 General elections.

20th - Atal Bihari Vajpayee after 1999 General elections.

21st - Dr. Manmohan Singh after 2004 General elections.

22nd - Dr. Manmohan Singh after 2009 General elections.

23rd - Narendra Damodardas Modi after 2014 General elections.