Here is the shabda roop of "guni" in the masculine gender, singular number:
Nominative: guniḥ
Accusative: gunim
Instrumental: guninā
Dative: gunaye
Ablative: gunit
Genitive: gunināḥ
Locative: guni
Note: "Guni" can also be used in the feminine gender, but it is less common. The feminine form would be "gunī."
For further clarification, you can refer to Sanskrit grammar textbooks or websites dedicated to learning Sanskrit.