How is entrepreneurship in IIM Lucknow?

It actually depends on what you are looking for. Almost all reputed management institutes provide exposure through case competitions, peer learning, etc.

In IIM Lucknow too, you would come across a similar incubator and an entrepreneurship committee cell. You need to join a cell and utilize whatever they provide you with. There you can brainstorm many ideas that can help you learn and understand various aspects that comprise entrepreneurship. These brainstorming sessions will also take place in front of the industrialists who will listen to you and supervise you in any particular event or any competition or even workshops. 

If you aspire to become an entrepreneur, join the E-cell, there you will have many chances to pitch in your ideas.