After submitting a revised manuscript (moderate revision was requested), what are the steps followed? I have submitted a manuscript to a reputed journal. After 2 months of peer review process, the response was “moderate revision has been requested” and they told me that the new version is required within 1 month.
After making the necessary adjustments, I have resubmitted the revised manuscript back on the 14th of October 2017. On the 21st of October the status changed from “with editor” to “under review”. To date (16th December) the status is “under review”.
In fact, I had made some readings about late reviews, I found that reviews are normally due 14 days after the invitation is accepted by the reviewer.
Should I worry about manuscript rejection?
Thanks in advance for your help
You may ask the editor in charge. I.e., send an email to the editor in charge of your manuscript. If you don't know who that is, send an email to the Managing Editor.

However, I don't think there's anything to worry about in this case: the change in status doesn't mean it is going to be rejected. It simply means they got your revision and now (sub-)reviewing it again.