I am confused about one journal that, there is any chance or not to accept my paper. That's why if I want to submit one manuscript in two journals simultaneously, what is/are the problem(s)? And is there anyone who have experience?
Submitting a paper to more than one publication at the same time is considered as a misconduct and a breach of ethical responsibility.
Submitting a manuscript to more than one journal at the same time is a waste of reviewers' time, and that time is precious to editors
The rationale for this standard is the potential for disagreement when two (or more) journals claim the right to publish a manuscript that has been submitted simultaneously to more than one journal.
Imagine a situation when two different persons claim one son. Horrible!!! Isn't it?
But before final publication, the journal authority take the permission of author once again. So, if one publication accepted in two journals, then before publish you have option to decide. But I agree on the point of waste of reviewers' time..