does intensity depends upon wavelength? if depends then how does it vaires according to vibgyor colour ?

Wavelength comes in if one is relating the intensity to number of photons emitted rather than to thermodynamic variables. In that case if we have sources of radiation of different wavelengths and all other variables, including rate of photons emitted, are the same for all sources, the intensity will be inverse to the wavelength.

This is because photon energy is proportional to frequency and inversely proportional to wavelength.