Can Drylock be applied to the basement wall while water is still seeping through. IF not how can I stop the water long enought to apply?
You don't want to just stop the water 'long enough', you want to stop the water, PERIOD!
Re-route storm water runoff away from your foundation, and put a dehumidifier in the basement. Then wait!
Thoroseal may be applied to a damp wall. In fact, the instructions recommend that you wet the wall first. That is how to get a good tight wall.
A lot would depend on how much water you have - damp? wet? seeping? gushing?