Wikipedia has this:
ɟɲ ज्ञ jñ roughly like argue
But those 3 writings all conflict with one another, so what is the correct pronunciation?
As far as I know, the [gj] pronunciation of ज्ञ is a modern regional pronunciation associated with Hindi-speaking areas, and doesn't have a classical pedigree (e.g. Panini). ɟɲ vs. jñ are not different pronunciations, they are transliterations (the former being IPA, the latter being traditional Sanskrit transliteration).