Answer:
DOWN
Step-by-step explanation:
When a positive charge is placed in uniform or nonuniform electric field then due to the Electric field present in that region the charge will experience electrostatic force on itself.
This electrostatic force is given as

here we know
q = charge
E = electric field
Now if charge is positive then force on the charge is always in the direction of electric field but if charge is negative then force is exactly opposite to electric field direction.
So here it will have force in the direction of electric field which is DOWN