School trip is exempted under gst..?

Yes its Taxable ,
As per notification 12/2017 CT (r) only following services are exempted provided by school

Services provided -
(a) by an educational institution to its
students, faculty and staff;
(b) to an educational institution, by way
of,-
(i) transportation of students, faculty
and staff;
(ii) catering, including any mid-day
meals scheme sponsored by the Central
Government, State Government or
Union territory;
(iii) security or cleaning or house￾keeping services performed in such
educational institution;
(iv) services relating to admission to,
or conduct of examination by, such
institution; upto higher secondary:
Provided that nothing contained in
entry (b) shall apply to an educational
institution other than an institution
providing services by way of pre-school
education and education up to higher
secondary school or equivalent.