I believe the RNA integrity number (RIN) is inferred based on the ratio of ribosomal RNAs (18S and 28S in human samples).
What is your sample of interest? If it's not a total cell extract, the RIN value is not relevant. Also, if you're using non-mammalian material, the RIN may be off.
RNA integrity number (RIN) values decides if RNA is good for RNA-Seq analyses or not. Normally measured using using the 28S to 18S rRNA ratio. if Lower than a threshold of RIN say 0.6 RNA will not considered good for sequencing and if you sequence will be risky. So if you face such a problem please send new RNA samples or take risk depending on projects.
RIN defines RNA quality/state and it is an algorithm based upon pre region, marker region, 5s region, fast region, 18s region, inter region, 28s region, precursor region and post region. Therefore, it is much better to express RNA quality using RIN value rather than using 28s and 18S ratio.
Dr. Fabio Alexis Lefebvre answered it with valuable expertise-- only eukaryotes whole-cell RNA has been subjected to angilent's machine learning process to generate the so-called RIN.
But plant celle seem fit for RIN too. Please see link below