Reiki and other energy workings might be able to be performed to help relieve stress and maybe assist with focus. But Reiki can't really grant intelligence per se.
if youare studying for school or a test, then try to find a way to make the knowledge the subject gives you exciting or engaging. Try taking a few minutes to look online and see how the lessons might apply in a practical way that you didn't expect. if you can connect yourself emotionally to what you are learning then it is easier to retain the information.
If you are looking for help for a more formal study method, I recommend a staged method.
Read the information you are studying. take a break, then read it again an hour later. Take another break and read it again the next day. then the next week, then (if there is time) the next month.
This gives you time to process the information and to remember through familiarity. it's like watching a new T.V. show. even if you like it, after watching an episode for the first time you might only remember the basic plot and maybe a particular funny or dramatic scene. But you watch it again and it reminds you on what you retained, plus adds a few details. it gives a chance for more of the plot to be remembered, and lets you see other subtle details you might have missed entirely the first time. Thus expanding and also enriching your memory. And the more familiar you become with the episode the more time you can spend looking more closely at the little details that connect the big ones together, making it come together and make sense.