Unexpected result with the GSM module A6
Apparently the SoftwareSerial library have some limitations, so I change the baudrate communication in the moduel ussing this sentence:


  AT+IPR=9600


And change the code that I upload to the Nano, changing the baudrate speed in the declaration, from:

mySerial.begin(115200);


to

mySerial.begin(9600);


And now all is well :D