Which B-School will I'll surely get if I do averagely good in GD-PI at a percentile of 94 in CAT 2017.

Hy
The CAT cutoff is expected to go high this year as the difficulty level ofCAT 2017was lower than the previous year. Generally, the oldIIMsand top B-schools such as FMS, University of Delhi, MDI Gurgaon etc. have CAT cutoff over 99 percentile. New IIMs and other top B-schools have cutoff ranging from 90 percentile or above. On the other hand, B-schools belonging to tier two to four can range from 80 to 50 percentile.

94 is a very good percentile for me but on a national level of you look at it then it is a average percentile and gdpi performance depends solely upon the aspirant.  There is no b school who give you admission only on the basis of percentile you really need to work hard after getting good percentile.
I wish you all the best.
Cheers !!

Unfortunately, this can never be guaranteed and so none of us can mislead you too. 94 happens to be a decent percentile and with fairly done justice to GD-PI,  you can convert calls of
*new IIMs,
*MDI Gurgaon,
*S.P Jain,
*K. J Somaiya,
* IMT, Ghaziabad
*IRMA
*IMI, New Delhi
*Great Lakes School of management, Chennai
*T A Pai Management Institute.
It's not just GD-PI that matters, now-a-days B schools look into a lot of other parameters as well. They are giving huge importance to academic and gender diversity right from PGP programme to FPM programme. Other than past  academic records are also given points and certain great achievements.
Anyway, with your percentile you will get certain good calls, try to give your best shot and you shall make it.
All the best!!