After digging various sites, found the solution and its working now
Even I can confirm that
2 finger right click is not working on Y510p.
Lenovo is also not updating drivers for Y510p. All the drivers are of 2013.
Do the following:
1. To re-enable two finger tap, press Windows key + R, enter "regedit" then press enter, and on the left pane browse to the following locations:
HKEY_CURRENT_USER\Software\Synaptics\SynTP\TouchPadPS2
OR
HKEY_CURRENT_USER\Software\Synaptics\SynTP\TouchPadSMB2c
(the first location didn't work for me, but the second location did)
2. In the right pane, double click on 2FingerTapAction and change the value to a "2" (Hexadecimal) forright click, or a "4" (Hexadecimal) for middle click.
3. Double click on 2FingerTapPluginID and clear any value it may have.
4. In the right pane, find the MultiFingerTapFlags key and change it from a 2 to a 3.
4. Additionally, if you want to enable three finger tap for middle click, double click on 3FingerTapAction and change the value to a "4", also clear any value for 3FingerTapPluginID and set 3FingerTapPluginActionID to "0".
5. Restart your PC and you can see the changes well enough.