How can I find out when an Editor intends to publish my paper? My manuscript was accepted in an ISI journal 6 months ago, but it is not published online yet. I found that the journal published online some manuscripts that were accepted after my acceptance date. Therefore, I sent several emails to the journal Editor but, I did not receive any answer.

How can I find when the journal aim to publish my manuscript?
Typically, a publisher uses an online system that allows authors to track the status of their paper. Double-check your inbox (particularly Spam folder) for a automatic email from such system (search the journal name for example).

If you are sure that you did not hear from the publisher and the journal editor within 6 months, I would say, it becomes worrying. The academic publishing was never a particularly fast process, but this situation probably oversteps the limits. Consider writing to the support team of your publisher and to Editor-in-Chief of your journal with inquiry. Also, consider sharing the name of the journal with your peers to prevent future misuse of anyone's precious time.