Would like to restrict some of the issue type fields to some specific users while creating an issue

[Gunjan Sood]

Would like to restrict some of the issue type fields to some specific users while creating an issue

[Eduardo Marques]

You can always use the Behaviours plugin: https://marketplace.atlassian.com/plugins/com.onresolve.jira.plugin.Behaviours

I'm using this to control who can insert information in specific fields either at issue creation or at issue edition.

[Deleted user]

Field level security settings are not possible: https://jira.atlassian.com/browse/JRA-1330

You could checkout the mentioned workarounds:
Workarounds
Higher in the thread Erik S makes a comment about a workaround that may be useful for some users:
http://jira.atlassian.com/browse/JRA-1330?focusedCommentId=55032#action_55032
it is documented further here:
http://confluence.atlassian.com/pages/viewpage.action?pageId=149834
Third party commercial plugin:
https://plugins.atlassian.com/plugin/details/23216