Devante:
The Motul oil you got is just about exactly the right oil for your motorcycle.
It's SJ API rating won't cause any harm.
Although I didn't look up the differences between the SJ and the SL ratings, I do know that a higher letter doesn't always mean the oil is better.
In fact, as KD5ITM mentions some of the "newer" higher letter oils have a much lower zinc content which for engines like the Royal Enfield which uses its engine oil to lubricate the transmission gears is not a good thing.
The JASO tests are all aimed at the compatibility of the oil with motorcycle wet plate clutches. If the oil has any of the JASO ratings, it will work fine in a Royal Enfield.
A word of caution: Don't trust the amount of oil that is specified in your Owners Manual that needs to be added to your engine.
If it's possible, measure the amount of oil you have drained out of the bike and replace it with the same amount of new oil.
I know the Owners Manual for my 2011 G5 says it needs 2.75 Liter's (2.9 US quarts) but actually it only needs about 2 quarts. 2.9 US quarts would be way too much oil.
As I understand it, that 2.75 liters of oil they mention is the amount of oil a bone dry, newly built engine would need. There are a bunch of nooks and crannies inside the engine that don't drain so when refilling after an oil change, it takes a lot less than the book says it does.