See How to Find Latitude and Longitude from location name.

/// Required Framework

     1. CoreLocation and 2. MapKit.

Import this two file where you use bellow method

#import <CoreLocation/CoreLocation.h>

#import <MapKit/MapKit.h> 

/// This bellow code work in < 5.0

  CLGeocoder* gc = [[CLGeocoder alloc] init];

    [gc geocodeAddressString:@"Set Your Location Name" completionHandler:^(NSArray *placemarks, NSError *error)

    {

        if ([placemarks count]>0)

        {

            // get the first one

            CLPlacemark* mark = (CLPlacemark*)[placemarks objectAtIndex:0];

            double lat = mark.location.coordinate.latitude;

            double lng = mark.location.coordinate.longitude;

            CLLocationCoordinate2D objCo;

            objCo.latitude = lat;

            objCo.longitude = lng;

            

            MKCoordinateRegion region;

            region.center = objCo;

            region.span.latitudeDelta = 0.03;

            region.span.longitudeDelta = 0.03;

            

            [objMapView setRegion:region animated:YES];// set region on your mapView

            MyAnnotation *ann = [[MyAnnotation alloc] init];// i just create this Annonation object for get and set location detail

            ann.title = strLocation;

            ann.subtitle = strDetailDesc;

            ann.anntag=11111;

            ann.coordinate = objCo;

            [objMapView addAnnotation:ann];

//            MKCoordinateRegion viewregion = MKCoordinateRegionMakeWithDistance(objCo, 0.03  , 0.03);

//            [self.objMapView setRegion:viewregion animated:YES];

        }

    }];

/// This is working in any ios

- (CLLocationCoordinate2D) geoCodeUsingAddress:(NSString *)address{

    double latitude = 0, longitude = 0;

    NSString *esc_addr =  [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    NSString *req = [NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?sensor=false&address=%@", esc_addr];

    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] encoding:NSUTF8StringEncoding error:NULL];

    if (result) {

        NSScanner *scanner = [NSScanner scannerWithString:result];

        if ([scanner scanUpToString:@"\"lat\" :" intoString:nil] && [scanner scanString:@"\"lat\" :" intoString:nil]) {

            [scanner scanDouble:&latitude];

            if ([scanner scanUpToString:@"\"lng\" :" intoString:nil] && [scanner scanString:@"\"lng\" :" intoString:nil]) {

                [scanner scanDouble:&longitude];

            }

        }

    }

    CLLocationCoordinate2D center;

    center.latitude = latitude;

    center.longitude = longitude;

    return center;

}

=> In this above method if your location not found then you get lat-long 0.0000

you can use above method it like bellow...

CLLocationCoordinate2D objLocaton =[appDelegate geoCodeUsingAddress:@"ahmedabad"];

NSLog(@"Location:%f && %f",objLocaton.latitude, objLocaton.longitude);