There are no "Dell authorized" service centers -- contact a Dell dealer in your area (best is to contact the selling shop, if you purchased at retail).  If you purchased online, you need to call Dell support -- service will be arranged if necessary by ship-in or onsite depending on the warranty you purchased with the system.  
Where is Dell Authorized service center in Madurai, Tamil Nadu
Where is Dell Authorized service center in Madurai, Tamil Nadu