You will need 30mm diameter rings for the Hi-Lux Optics Top Angle 3-12x50mm Rifle Scope. Now the height will depend on what base you are using and the rifle you are mounting it to. The guide at the link below will help you determine what height rings you need. If you are mounting the Hi-Lux Optics Top Angle 3-12x50mm Rifle Scope to a picatinny or weaver scope base the rings at the link below will be a good option.
https://www.opticsplanet.com/howto/how-to-how-to-measure-scope-height-scope-ring-height.html
https://www.opticsplanet.com/vortex-30mm-riflescope-rings.html?_iv_parent-tube-diameter=30-mm&_iv_tube-diameter=30-mm
Hi-Lux Optics does not provide specific recoil information on the Top Angle 3-12x50mm Rifle Scope. I would recommend reaching out to Hi-Lux Optics directly for more information. You can find their contact information below:
https://hi-luxoptics.com/pages/contact-us