@Geeta,
One should not wear Ruby and Blue Sapphire at the same time, they don’t go well with each other and hinder the positive energy. So you will not get benefit.
Ruby and Yellow Sapphire can be worn together on same hand and same (or different) finger at the same (or different) times.
Yellow and Blue Sapphire are also not advised to be worn together.
Wishing you good luck, God bless and above all…
CHEERS!!!