Teachers can approach conciliation officer under industrial disputes Act?

Whether private recognised school teachers can approach conciliation officer under industrial disputes Act for their employment or non employment grievances?

NO. Though education is an industry, teacher is not a workman. Therefore teachers in schools and colleges can not seek remedy through any authority under the Industrial Disputes Act,1947.

for their grievances of private school teachers where they have to approach in connection with salary matters termination matters etc?

They can approach civil court of their area for their fight.

Dear Teachers
Unfortunately there is no grievance handling mechanism in India for teachers and educational institutions are exploiting the college/ school teachers. In my opinion civil court will not give you speedy remedy and you may approach High court under article 224 and file a writ petition.
You can raise your voice in High-court under art 224 as there is a provision of right against exploitation ( Fundamental Right) in our constitution. This option is speedy and give better result.
Teachers are the building block of our society and in primary school we can get a teacher at the rate Rs 2000/- pm, while we are unable to get the sweeper at the rate 10000/- pm.
Thanks & Regards
Charan