Vanakkam!

yes, there are possibilities as well as impossibilities.

it depends upon the institution you are in. in many private schools, if they have less strength or any vacancy in the group you ask, they might allot you. but this happens only within the first few weeks of school starting. after which neither can they change nor can you cope up with the portions.

some schools are stubborn and they dont really change groups and some charge you some fee and ask you get new admission in the same school. so new roll number, id everything.

in the government schools, it is not at all possible.

but all these are only when you have the eligible mark for vio/math grp. or else you wont get in any school. maybe you can get by some recommendations or donations. but it rarely works in our state.

i hope it helps you