Hi @Sravani87, let me see if I can help out here!
In order to do a factory reset, Find and tap Settings > Backup & reset > Factory data reset. But if you your phone is malfunctioning and you suspect that the software in the phone is the root cause, I would suggest that you try to repair the software instead of doing a factory reset. This due to the fact that a factory reset will only erase user data whilst a software repair will replace your current software with a new one.
Keep in mind though that both a software repair and a factory reset will erase all user data from the phone, so remember to do a backup before any of the measures in order to prevent data loss.
I hope that answered your question!
