sir i would get production ,civil, metallurgy or chemical at nit trichi.

but my preference is mechanical engineering.i have got mechanical at amrita university coimbatore? should i go for nitt and take any course offered to me or go to amrita.what are the possibility of sliding to higher branches at nit , if yes what is the cretiria

it would be better if you take nit trichi because the placement of nit trichi is much better than the amrita.

also if you are interested in mechanial engg then you can take production in nit trichi because both of these branches are similar and in many colleges many of the courses are same and they have combined classes for production  and mech.

although civil and chemical are also good option if wanted to take. you can get good job offer in these branch also. And try not to take metallurgy because it dont have much scope in present day.

the criteria of sliding to higher branches in nit is they see your performance of 1st year(2 semesters) and after that if you have good CGPA then you will get promoted to higher branch. Generally the requirement of CGPA for sliding to higher branch is aroung 9 or more.