8. Please refer to the following provisions of Finance Act, 1994.
"66D(l) services by way of-
(i) pre-school education and education up to higher secondary school or equivalent;
(ii) education as a part of a curriculum for obtaining a qualification recognised by any law for the time being in force;
(iii) education as a part of an approved vocational education course;
65B (11) "approved vocational education course" means,--
(i) a course run by an industrial training institute or an industrial training centre affiliated to the National Council for Vocational Training 2[or State Council for Vocational Training] offering courses in designated trades notified under the Apprentices Act, 1961; or
(ii) a Modular Employable Skill Course, approved by the National Council of Vocational Training, run by a person registered with the Directorate General of Employment and Training, Union Ministry of Labour and Employment; "
Thus, negative list covers the above 3 types of courses and vocational course is defined as above, at present. Apart from this, services provided by an educational institution (defined as below) are exempted under Mega exemption Nofn.25/2012-ST.
[(oa) “educational institution” means an institution providing services specified in clause (l) of section 66D of theFinance Act,1994 (32 of 1994);]
Analyzing your case in the above framework, short term commercial coaching / training courses are taxable, no doubt.
Regarding DOEACC (Department of Electronics and Accreditation of Computer Courses), please check whether the qualification / degree awarded at the end of the course is recognized by law for the time being in force or it qualifies to be the vocational course within the definition extracted above. If yes, it is not taxable. Otherwise, even such courses are taxable.