Tantra and Yoga are two diametrically opposite spiritual practices though they have the common goal of achieving Self-realization. Both are techniques that are used by spiritual aspirants. The main difference between the two is that Yoga is a technique where you apply control over yourself with complete awareness while Tantra is a technique where you do not use control over yourself, but instead you indulge yourself with complete awareness. In Tantra, there is no opposition to your natural impulses, instead you use your nature to go beyond.

Yoga is the technique of putting a stop to the disturbances of the mind. The ordinary mind is destroyed by its own desires, and Yoga is a technique to put a stop to your desires, to become desireless. For example: Sex is a basic energy you are born with. In Yoga, you must fight with this energy, and overcome it. Yoga neutralizes your mind and thereby helps you to experience the ultimate Reality. Tantra on the other hand, is a technique which asks you to be aware of your desire, to move in the desire with full consciousness but without being involved in it, and to continue to do so until you transcend it.

No, Tantra is not advised as a tool for Self-realization for the common people. The mind is very cunning, and it is not easy for a not-so dedicated spiritual aspirant to indulge in desire with complete awareness but without being involved in it. So, Tantra is recommended only for very ardent and committed spiritual aspirant.