Chellamral,
Is the bougainvillea in a pot or large container?
Some people use eye hooks that you can drill into the bricks or concrete with a small drill bit, not too invasive.
Then they buy wire and train the vine up that, however you would like.
They sell this cheap at big box stores.
It looks pretty nice because you really can't see the wire and it looks like it is climbing up the concrete on its own.

The thread on hooks on the forum has your answer.

Here is a link that might be useful: Hooks for concrete