Hello,

NTSE is conducted in two stages - stage 1 is conducted by the States/UTs and stage 2 exam is conducted at national level by NCERT. The stage 1 of NTSE is conducted in November at state level while the national level is held in May. The notification will be released in July. 

Check this link for more details - https://school.careers360.com/articles/ntse

I'm give practical exam 19march 2018