If I charge my mobile from different charger what happens?
No, it will not damage your phone. As long as it's a micro USB charger, it will be fine.

5.5V is fine, I've had success with 6 Volts from a homemade charger, and you won't meet voltages higher than 5.5V on a micro USB charger anyway. Extra Volts are dangerous, so it's good to be cautious but 5.5V will not do any harm.

The current rating (Amperes, A) does not count; if it's too low, the phone may charge slowly or not at all, but higher rated chargers will not do harm.