Is there a scene at the end of the movie, after the credits of men in black 3?
No, Men in Black III offers no extra scenes either during, or after the credits.
The movie, directed by Barry Sonnenfeld was released on May 25, 2012, and stars Will Smith, Tommy Lee Jones, Josh Brolin, Jemaine Clement, Alice Eve, and Emma Thompson.
In the film Agent J (Will Smith born Willard Christopher Smith Jr., on September 25, 1968 in Philadelphia, Pennsylvania) travels back in time to the 1960s to prevent the assassination of Agent K (Tommy Lee Jones, born September 15, 1946 in San Saba, Texas).
MIB3 marks the longest time that Smith has gone without appearing in a film since his film career start in 1993; it's been 3.5 years since his last film, Seven Pounds, in December of 2008.
He won't be repeating that absence for a while, though, he'll be in After Earth in 2013, Winter's Tale in 2013, as well as Hancock 2, Bad Boys 3, and I, Robot 2 all likely to be released within the next 3 years.