sometimes i am getting problem in software updates. So i would like to get only essential security updates and also need to make it as default. Please let me know is there any way to sort out that?
All security updates are essential. Otherwise they would not be "security"updates.
See software&updates for the options you have:
The top checkbox is about "important security updates" so keep that one active. If that is all you need uncheck the other 3.
The 1st 2 dropdown boxes let you set when these are checked and what is done when there is an update (display, download or download+install).