NIT Hamirpur - National Institute of Technology Answered Questions

Sorry but for admissions to NITs candidates should have secured at least 75% marks in class 12th exam or be in the top 20 percentile in the class 12th exam conducted by the respective board. For SC/ ST candidates, the eligibility criteria is 65% marks in class XII.
Your score is 69.7%, so you would not be eligible for admission.

You can check the previous year's category wise cutoff ranks at: https://josaa.nic.in/josaaorcrarchieve/Result/OpeningClosingRankArchieveN.aspx?Year=2017.
The cutoff for this year's round 1 counselling at: https://josaa.nic.in/webinfocms/Public/View.aspx?page=71.
There you may get an idea of your selection.
Best of Luck.

After seven rounds of JOSAA counselling, if the majority or considerably large number of seats remain vacant in some colleges, then these colleges combinely Under Central Seat Allocation Board conduct a special round as a special opportunity to students who want to apply again. Note, it's not necessary that all colleges participate in it.
Best of luck.

When the question is among the college and branch, definitely go for the branch.
Simple reason for it is that you can change your college at any point in time but your branch comes along throughout the life. Also, a low branch from an elite institute will be a short-term comfort but a good hard work in core branch from an average college will be worth it and reward you more.
Best of luck.

No, you would not get NIT Because
Eligibility For admissions to NITs/ IIITs/ GFTIs, candidates should have secured at least 75% marks in class 12th exam or be in the top 20 percentile in the class 12th exam conducted by the respective board. For SC/ ST candidates, the eligibility criteria is 65% marks in class XII.