What does Rani mean?
From Sanskrit 'rajni' (rani), the feminine of 'raja', meaning 'queen'. Used for both a queen regnant and a raja's wife across the Indian subcontinent and Southeast Asia.
What does Nishka mean?
From the Sanskrit निष्क (niṣka), an ancient gold coin, and by extension a golden necklace or ornament — attested in the Manusmriti and other classical texts. Popular 'pure/honest' glosses on name sites are not supported by the classical sources.