TOEFL

the gmat cutoff was 600 and apart from that TOEFL is not necessary but a good score in that is a usual bonus and an upper hand over the matters.

Your class 12th score is low, as they generally require at least 60 percent in the boards and you have a lot less so not sure about passing the criteria.

Plenty of online materials are available for studying IELTS or TOEFL. First understand your areas of strength and weakness. Practise according to that.

Yes, you can get really good universities in US, if you apply and even things like where you pursued your UG, in what all activities you have participated will be considered before admission.

Hii Nagulavancha
No it's not mandatory. My best wishes
All the best.

Pass score depends on the college you apply for. Generally, 310+ out of 340 is considered a good score in GRE. In TOEFL, 80+ out of 120 is the minimum eligibility criteria of English proficiency. In GRE. The verbal section is very hard, so you need to prepare well for that. TOEFL is easy, just a month preparation is enough to score well.

To do Masters in Canada, IELTS is must but some colleges can accept TOEFL too. In Australia, IELTS is mostly accepted in colleges. So, I personally suggest you give IELTS exam. Also, GRE is not mandatory, but it will enhance your application and you might stand out from other students, so there's more chance to get the admission.