Is it possible to buy a Canon 65mm MP-E and a special ring to make it fit onto a Nikon?

I'm still pretty new to Macro Photography and I was looking for a better lens than what I have now, my lens only goes to 1:2 magnification and I want to go way beyond that.

I've read about bellows but I think lenses are the better way to go for taking photos such as insects etc. I see that Canon made a lens that goes up to 5x magnification. Since I have a Nikon, this lens abviously won't fit. Is it possible to buy a ring to make a Canon lens fit onto a Nikon? If that is possible, is there any downfalls to it?

Or does anyone have any suggestions for how I can get super close up micros with Nikon equipment? Thanks!

Added (1). I do have extention tubes, I have a lens with aperture control on the lens but I have to be centimeters away from the subject

Have you considered macro extension tubes?