Most likely a variant of Nila, meaning dark blue.
Nyila is a modern spelling variant of the name Nila, which has roots in Sanskrit referring to the color sapphire or dark blue. It is also occasionally associated with the Nile River in Africa, though this is a secondary etymological connection. In recent years, it has emerged as a unique choice for parents seeking a melodic, vowel-heavy sound.
Less common today
Nyila isn't in the latest US Top 1000. It last peaked at #10,972 in 2011.
US births per 5-year period, 1990βpresent (SSA data).