What does Om mean?
From Sanskrit Om (ॐ), the sacred primordial sound and mantra regarded in Hindu tradition as the essence of the universe. Used as a name it carries that whole spiritual weight.
What does Shivansh mean?
A modern compound of Shiva and amsha (अंश, 'portion/part'), read as 'a part of Lord Shiva'. A contemporary devotional coinage rather than a classically attested name.