There are four typological classes of consonant letters:
Those with full-height descenders/ascenders, for example ka, tha, and ma. This is the largest group.
Those with short ascenders, for example pha.
Those with rounded tops, for example ja and la.
Those with right-facing hooked tops, for example jha and ha.
Anshuman Pandey, Proposal to Encode the Kaithi Script in ISO/IEC 10646 2007