Hi Akhlakh,

KVPY, NTSE, IMO, ISo are all school level examination usually conducted at 10th level for NTSE, IMO and ISO.

While KVPY is conducted at 11th, 12th and graduation first year. So, if you get yourself enrolled in the undergraduate programme and fulfil other requirements you can sit for KVPY exam. For more information on KVPY exam, you can read the complete article here - https://school.careers360.com/articles/kvpy?icn=kvpy_article&ici=kvpy_exam_rdmrvp

all the best

olympiads and kvpy has to give before 12th. but if you are droping the year then u have to check on its official sites.