In this article i will take you through the following steps listed below

RECOVERY MODE
1.Using Hardware Buttoms
2. Using ADB(Android Debug Bride)
3. Using Quick Boot App

The stock recovery that comes pre-installed on your device doesn’t support touchscreen mechanism. You’ll have to use the Power and Volume buttons available on your device to select and navigate between options in the recovery. There are multiple methods to boot your Galaxy S3 in recovery mode.
The most handy (and hardware coded) method is about pressing a combination of keys for a few seconds on your Galaxy S3. Others are software based, let’s have a look them below:

1) Using Hardware Buttons Mode

This method is a fail-proof method that’ll always work for you, unless you’ve broken one of hardware keys. In such a case you’d be left with only the other two methods discussed below.

check the source link for more
Source http://www.iconis.info/2015/04/boot-your-samsung-galaxy-s3-in-recovery.html