Yes, I was following the old guide for making the connections - http://ardupilot.org/copter/docs/common-rangefinder-lidarlite.html
But, I recently found out that there has been change in pinout wires from the lidar and the above guide does not work for Lidar Lite V3.
Finally, I referred to the official manual by Garmin - https://static.garmin.com/pumac/LIDAR_Lite_v3_Operation_Manual_and_Technical_Specifications.pdf
After changing the connections, I got the lidar working with both I2C & PWM as I am getting the Sonar Range. Just to mention, I am getting Sonar Voltage in PWM only and not in I2C.
Also, I found a new guide/manual for making correct connections & settings of Lidar Lite V3 with PixHawk running on ArduPilot firmware - https://www.lambdrive.com/depot/Robotics/Controller/Firmware/ArduPilot/LIDAR-Lite.html#connection
Please do take a look and update the ArduPilot's official wiki with respective changes for connecting Lidar Lite V3. It will save time and will help others who are working with V3.
1. Firmware installed - APM:Copter V3.5.0-rc6 (efab409b)
2. With I2C approach, I connected the lidar directly to pixhawk (without adding the capacitor but it is recommended as per the official manual)
3. With PWM approach, I added a 470 Ohm resistor as guided in official manual by Garmin.
Thanks for your support.