I am working as Java Developer since 4 years and also I passed Java SE 6 certification in 2014 and now planning to upgrade my Java knowledge and looking to take certification.
I am confused which version should i choose from java 7/8/11.
Any help would be appreciated.
Find out about the upgrade exams; some of them are going to be withdrawn at the end of February 2020. If you can't pass an upgrade exam in that time, you will have to sit the OCA for Java8 or the OCP for Java11 (part I). Go through the Oracle website and find out about their syllabi. See which suits you better.