A middle aged women presented with right sided hearing loss Rinne's test shows positive result on left side and negative result on right side. Weber's test showed lateralization to left side,diagnosis is -
Rinne’s Test
Negative on right side means either there is:

Conductive deafness of Right side or
Severe SNHL on right side (leading to false negative Rinne test)

To differentiate between the 2 conditions: Let us see the result of Weber’s test:

Patient is complaining of decreased hearing in right ear and Weber’s test is lateralized to left ear (as stated in the question) i.e. to the better ear.
As discussed in the text: Weber’s test is lateralized to the better ear in case of SNHL.

So, diagnosis is right sided severe SNHL.
Remember: If Rinne’s test is negative and Weber’s test shows lateralization toward healthy side, it indicates severe SNHL
Right sided conductive deafness
Right sided sensorineural deafness
Left sided sensorineural deafness
Left sided conductive deafness