Random.insideUnitSphere

Description

Returns a random point inside a sphere with radius 1 (Read Only).

    // Sets the position to be somewhere inside a sphere
    // with radius 5 and the center at zero.

    transform.position = Random.insideUnitSphere * 5;

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Example() {
        transform.position = Random.insideUnitSphere * 5;
    }
}