Question

how many tangents, parallel to a secant can be circle have?

Answer 1

The answer is two.

A tangent is a line that intersects a circle at only one point on its circumference. On the other hand, a secant is a line that cuts through a circle such that it touches at two points of the circumference.

Therefore, a circle can have a maximum of two tangents parallel to a secant.

Answer 2

The answer of your question is " Two''

There are two tangents , parallel to a secant   that can be drawn at circle. 

A tangent is actually a line which intersects a circle in  the exactly one point  while on the other hand a secant is a line which intersects a circle in exactly two points or touches the two points of circumference of a circle . SO when you draw tangents parallel to scant there can be only two tangents that drawn. This could  easily observed upon drawing the circle and then scant and tangents .