I got the solution that is
"
1) First send the police and the thief
then the police comes back
2) now send the police and 1 boy child
then the police and thief comes back
3) now send the father and the boy child
then the father comes back
4) now send the father and the mother
then the mother comes back
5) Now send thief and police
father come back
6) Now send father n mother
Mother comes back
7) now send the mother and a girl child
the police n thief comes back
8) Now send police n a girl child and police comes back
n Now the thief goes with the police
"
Sandeep Tomar