Question

what is the SI Units of G: and write the value of G in SI Units

Answer 1

Did you meant gravitation constant
If yes then answer is 6. 67×10^-11 N.Kg^-2. m^2

Answer 2

si unit of g is Newton miter square per kg minus2
$6.673 \times 10 minus2 newton {m}^{2} kg {2}$