To get an approximation to the RGB of the tint value, you need a bit of arithmetic:
If the RGB of your Pantone colour is (0, 101, 96)
and the background is pure white, i.e. (255,255,255)
then a 50% tint is pretty much halfway between the two - and that calculation is done for each of R,G,B separately. And the answer is: R=127, G=178, B=176 . That's because 127 is about halfway between 0 and 255. 178 is halfway between 101 and 255. 176 is about halfway between 96 and 255.
To get a tint of N (where N is in the range 0.01 to 0.99; 0.01=1%, 0.99=99%): for each colour value X in RGB, take [N x X] + [ (1-N) x 255], to get the RGB value of your tint.
So, if you wanted a 30% tint of your (0,101,96), 30% = 0.30
So, R = [0.3 x 0] + [ (1-0.3) x 255] = 0 + 179 = 179
and G = [0.3 x 101] + [ (1-0.3) x 255] = 30 + 179 = 209
and B = [0.3 x 96] + [ (1-0.3) x 255] = 29 + 179 = 208
i.e. RGB = (179, 209, 208)
But remember - when you convert between Pantone and RGB; or between Pantone and CMYK, you're going to change colours a bit. Every time. What "the right thing" to do is, will depend completely on what your end use is.
Are you by any chance creating an application for a monitor (e.g. a web page), based on a corporate colour scheme that's specified in Pantone colours? That's one of the few occasions where converting from Pantone to RGB would be a safe thing to do - because it's inevitable, it has to be done, because the end user is going to see it as RGB.
If it's for any print application, then use an application (such as InDesign, Illustrator, Photoshop) that will preserve the Pantone number, and tints, in that form.