I think, before asking a question in this forum (and using very valuable life time of other people!) it should be requested to look first into a fundamental book about diffraction of crystal or material science, or use some other sources like Wikipedia. There is no doubt that in case you don't understand there everything that you can ask you question and we will certainly help you, but this kind of question is so fundamental that nobody even want answer on it. It is thousand times written somewhere, and in a better way we could do it here in some short sentences.
Each ring in electron diffraction pattern represents a lattice plane in a particular (h,k,l) direction. The crystal acts like a grating to the electron beam. Electrons get scattered when they enter into the crystal. The wavelength of electrons (de Broglie wavelength) is in the order of the inter atomic distance in the lattice. The crystal planes satisfying Bragg's condition with the electron beam will leads to concentric circles having direct beam at the center. The interplanar distance can be known from the diameter of the each ring. In X-ray diffraction, each peak corresponds to a single latticle plane having Miller indices of h, k, l. Hence the number peaks in X-ray diffraction must be equal to the number of rings in electron diffraction.
I think, before asking a question in this forum (and using very valuable life time of other people!) it should be requested to look first into a fundamental book about diffraction of crystal or material science, or use some other sources like Wikipedia. There is no doubt that in case you don't understand there everything that you can ask you question and we will certainly help you, but this kind of question is so fundamental that nobody even want answer on it. It is thousand times written somewhere, and in a better way we could do it here in some short sentences.
Take any book about any diffraction on crystals, take simply into account that electrons as well as x-rays, neutrons, protons are describable as waves and exchange the source of radiation and you should understand that the fundamental approaches are equivalent. Of course there are specific properties of each of these diffractions like absortions, maximal spatial and angular resolution, but the general phenomena "diffraction" is the same.
Coming back to your question: already there the first part is mistaking since the number of reflections in an XRD diffractogram already depends on the angle range you selected...and the radiation you are using! How the number of rings in electron diffraction can then be the same compared to an indestinctly defined number of rings or reflections in XRD?