Whic one is better between gps add on v2.0 module and gps module ublox neo 6m if I ise this one raspberry pi 3?
There are many GPS modules on the market. Which one is better - depends on particular purposes and personal taste. Most of them are very similar.
GPS modules typically have standard UART interface, so you can connect any of through UART interface to GPIO 14, 15 (UART RX and TX). Just check you desired GPS module specifications about signal voltage level (they should be 3.3V; otherwise use any 3.3<->5V converter). Furthermore, you can use software UART emulation and connect GPS UART pins to any GPIO pins of Raspberry Pi (as communication speed of GPS modules is rather low due to low amount of data to be sent and relatively slow work of positioning system).
Then you have raw text data on the output of the UART interface, which contains GPS data: coordinates, time etc. You can save it into a file or process in application that can handle raw GPS data, or in your own program.
You should also read each specific module documentation to handle it correctly or find ready-to-use implementation of the specific module made by someone earlier. But, again, they are very similar and vary only in details.