Guys got permanent solution for auto restart issue. That is cpu reballing.

[mukundhanr]

Give your phone to well professional technitian to do cpu reballing which costs 2500 and you will never get the problem back. You can give your device to bluestar mobiles in banglore or Rajan mobiles in Tamil Nadu

[Sid_Karna]

Well Samsung will replace motherboard for 1500 or less, sometimes free.
please check out this post.
https://r2.community.samsung.com/t5/Galaxy-M/ALERT-Those-who-have-restarting-problem-should-follow-t...