It's unclear whether you mean after you have stopped being Prime Minister, or as soon as you become Prime Minister.
If you mean during the term of a Prime Ministership - there are a whole lot of things that you can't do, according to whatever national constitution you're talking about.
If you mean, after a Prime Minister finishes his or her term - there is very little restriction on what you can do, since you are simply a private citizen. Many countries, such as Australia, pay former Prime Ministers' travel and office allowances, so they can do things like compile memoirs and give speeches in various places.
Former Prime Ministers will sometimes make contributions to politics, but in general they are expected to stay of day-to-day political questions.
Many former Prime Ministers make careers in other areas such as business, for example.
when the achudhanandhan became prime minister
Harold Holt was born on 5 August 1908, and became Prime Minister in January 1966. He was 57 when he became Prime Minister.
He was Prime Minister in the eighties.
Hitler became Prime Minister of Germany in 1933.
Robert Walpole was 44 years when he became prime minister.
Narendra Modi became the prime minister on May 26, 2014.
Oqil Oqilov is the Prime Minister of Tajikistan.Oqilov became the 7th Prime Minister of Tajikistan on 1999.
Winston Churchill became the Prime Minister of the UK during WWII.
On May 13, 1940 Winstion Churchill became prime minister of Britain.
Mahamadou Danda was the Prime Minister of Niger at the start of 2011.Brigi Rafini became the Prime Minister of Niger on April 7.Danda became the Prime Minister of Niger on 2010 February 23, and left office after the 2011 presidential election.Rafini became the Prime Minister of Niger at the same time Mahamadou Issoufou became President of Niger.
Yes, Arthur Meighen Prime Minister became the 9th Prime Minister of Canada.
Daniel Hodge is the Prime Minister of Curaçao.Hodge became the Prime Minister of Curaçao on 2012 December 31.