* बच्चू (bachchu): This is a generic term for a young one or a baby, and it could be used to refer to a cockroach nymph.
* लार्वा (larva): This is a scientific term for the larval stage of an insect, which includes cockroach nymphs.
* पिंडी (pindi): This word is sometimes used for a cockroach nymph, although it's not as common as "bachchu" or "larva".
Ultimately, the best way to refer to a cockroach nymph in Hindi would depend on the context and the level of formality you need.