How can I get coordinates of robot position? lat, lon? x ,y?

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1. Wheel odometry for a short term reference, or long term reference that will accumulate error
2. LIDAR with a Monte Carlo Localization (AMCL) method and prebuilt map
3. LIDAR with SLAM

I'd say these are the 3 most common. Any other number of methods including wifi, AR tag, sound etc. are out there but are less common considering the low cost and high reliability of LIDAR. If you are outside then you can use GPS.

This is really a question too general for RA and there are many sources across the web that will be more useful for you. If you are looking for specific packages please edit your question.

EDIT A specific package to consider is robot_localization