What does Ansh mean?
From Sanskrit amsha (अंश), 'portion, share, part'. Often used affectionately to mean 'a part of oneself' or a share of the divine.
What does Ishan mean?
From the Sanskrit ईशान (īśāna), 'ruler, master'. It is an epithet of the god Shiva, also denotes the sun and the north-eastern quarter (one of the dikpalas). A genuine, well-attested Vedic/classical term.