Hi Radha, relax take it easy.
N:P:K reflex the Nitogen Phosphate and Kalium (Potassium) most of the commercial fertilizer they will display the above ratio. N:P:K: 19:19:19 indicate that this fertilizer is good for the growing (balance) of young orchids ,also can be used for mature plants . N:P:K: 13:27:27 example this one mainly use for stimulate or encourage the formation of flower spikes. High Phosphate and high Potassium is very important for blooming in contrast high Nitrogen may inhibit the spikes formation and encourage growing of the plants.Hope this will help you.Good luck