Your 18350 should fit, most adjustable chargers accommodate them. I would check the amp output of the charger to make sure it is not too high for them.
I don't know if you know this so just in case, all these batteries are lithium ion. The Li-mn, also known as IMR, is just a version of Li-ion and are considered safer chemistry. There is also ICR Li-ion which are considered less safe to vape on if they are protected and not at all safe if they are not protected. If you are unsure what your 18650s are, tell us their make and model and we can possibly figure out what they are.