Certainly not, I have said it before, safety considerations trump religious freedom. Taser can do somebody serious damage. However, you may be permitted to carry something similar.
Let us say you approach the courts with a well developed religion. You have a Holy Book, you have your God, your Commandments, creed etc. One of the creeds of your religion is that you must carry a taser at all times. Only one of them mind you, not the only creed. You cannot fool the justices, they are no dummies, they know when somebody is trying to take undue advantage of the freedoms.
But let us say you have several requirements for your religion, and carrying a taser happens to be one of them. Carrying a real taser would still be out of the question, the danger involved is too high. However, if you can design a smaller, micro version of the taser, which would give a shock of say 1 or 2 millivolts, then you may be able to carry it to a public place. That will have to be decided by the courts.