i am able to create the required field but it is getting under "DETAILS SECTION"
but i wanted to add that field to be under "PEOPLE SECTION"
Can anyone help me out in this
For a field to be relocated into the people section, it needs to be of a type Jira thinks of as "a person related field". This means you will need it to be a field that presents itself to Jira as a user-picker, multi-user-picker or group-picker.
I'm guessing you have added a text or select field?