Glitch Pokémon are defined as data that is mistaken as Pokémon species by the games. Beta Pokémon are early concept Pokémon that were cut from final games, often inspiring existing Pokémon. In Kogranar, both of these types of Pokémon can only be found in the Lost Lands dungeon, which is unlocked after completing a quest specific to it. This quest is received after reaching a certain team rank.

When you have a glitch Pokémon, you may pick any form you'd like!

As of current, there are no recruit items for Beta/Glitch Pokémon nor are there ways to roll them in dungeons aside from the Lost Lands. This will be adjusted for the future!

Both Glitch & Beta Pokémon can evolve according to their Bulbapedia article or according to their inspiration. For example, a 'M can evolve into a Clefairy at Lv.80. These evolved Pokémon will be marked with a β (Beta) or Glitch note after the traits depending on what kind of Pokémon they evolved from.  A non-Beta Pokémon can evolve into a Beta at the condition that said Beta Pokémon is in the inventory. 

Those Pokémon will have a note on their genome as such: LVL??? [Nosepass | Variant | β Glitch]

Glitch & Beta Pokémon can be used for breeding as long as they are at the required Lv.30. If an egg results in a Glitch Pokémon (or a fusion), the glitch stays as is.

However, many Pokémon have a low chance of giving a Beta off-spring if they have a Beta version. If the off-spring results in a Beta Pokémon (or a fusion), the pre-evolution will be obtained rather than the form the parent was.  These will also have a β note.