Can B-tech failed rejoin b-tech once again from first year?

You can do B.Tech again by joining in the first year B.Tech. You can rejoin and you have to finish the course within eight academic years from the date of your first admission into the course. Otherwise, you have to discontinue the course after the prescribed duration.
You have to decide based on your interest in the subject and your capability of completing the course within that prescribed time period. So before joining again you should think thoroughly and decide. If you feel that engineering is not your line, you can think of doing other courses like BA, B.Sc or B.Com and then you can think of going for further studies. You are the best judge and you decide as per your confidence levels.

There is no question of any denial from the authorities if you gearing up for your second attempt for taking up the fresh course of B.Tech. However, you should consider the time span which you would devote in completion of the said course. The normal tenure of this course is of four year but in your case, you need the double time for completion of the same since you have been rewarded NFTE indicating that a fresh continuation of the said course would be possible only possible after the expiry of the normal duration of the course.
Keeping in view of other possibilities where you can do still better in terms of academic achievement by taking up a course of your passion such B.A pass course with Economics and English or B.Sc ( Honours) in Mathematics or a diploma course in computer would prove to be quite advantageous in your case. Saving the time should be your crucial goal apart from achieving some career which has huge demand in the current market. You need to review your decision.