Is the equipment nuclease free so as not to degrade your sample? What volume are you loading? Typically need around 200 ng to visualize on agarose. You should get a 18s and 28s band. If sample is degraded you will only see a smear
The concentration seems too low. I think you need to re-extract the RNA from your sample and recheck the purity and concentration. You can run it on agarose gel if the concentration is more than 200 ng.
The other factors affecting RNA quality are high voltage and contamination as RNA is highly unstable. Be cautious while the RNA extraction process. I hope this will work.
RNA concentration is low. Also, storage of RNA matters and it degrades easily. Always store right away in -80 and make 5-10ul aliquot after extraction for gel visualization and quantification. if it degrades, you can use the stock.
Did you get the value of the concentration by Nanodrop? Remember that Nanosrop gives a value but does not discriminate between degraded material or not. What is the detection method? What is the RNA extraction method. I consider that the initial concentration is low. I suggest placing another known sample on the same gel and testing.