Q: What is the difference between SJIF and RJIF and which is a better indicator of journal quality?
I have submitted my article at a time in two journals showing one SJIF 3.7 and another RJIF 5.2. Is there any problem of submitting in two journals at a time? What is the difference between SJIF and RJIF?
It is unethical for authors to submit the same papers to more than one journal at a time. In publishing circles, this is known as simultaneous submission and is frowned upon. Screening every submission requires a lot of time and effort, and if two or more journals process the same paper, the entire cycle is duplicated, thus leading to a waste of academic resources. If you have more than one target journal in mind, consider sending a pre-submission query to the journals. You can send as many pre-submission enquiries as you wish, but you must always submit your paper to one journal at a time. If your paper is rejected by a journal, you can consider sending it to the next one.
You also wanted to know about the difference between the SJIF and the RJIF. The SJIF refers to "Scientific Journal Impact Factor" and RJIF to "Research Journal Impact Factor." The former is an indexing service for journals while the latter is used to evaluate the prestige of journals. Both products are owned by different companies and could be considered offshoots of the Journal Impact Factor (by Thomson Reuters). Even though SJIF and RJIF exist and are used by some (not a majority of) journals, they are not considered in major academic decisions, e.g., those related to tenure. Also their credibility is not yet established, whereas the JIF, being patented by a well-established company is well known and comparatively more credible. Note that publishing in a journal with a high impact factor is not the only way or even the best way to advance your career or boost your profile.