Please check out the below link including related articles, and see how Christian missionaries are actively targeting the Sikh community worldwide.
Unfortunately there is a rising trend of Sikhs converting due to lack of knowledge/awareness of Sikhi. They have a dedicated website - www.sikhoutreach.org
http://www.commissionstories.com/asia/stories/view/sikh-pastor-has-a-vision-of-transformation
Sikh people are open to the Gospel, Singh says.
“Sikh people need Jesus, and Sikh people are in search of God, but they just need a little bit indication that this is the true way,” Singh says. “Whenever they come to Christ, they come in full faith. They will not slide back.”