KBC is going on air Sep 6 on Sony channel.
"We were excited to sing along with the Bollywood superstar in 'Kaun Banega Crorepati', " said Neil Nongkynrih, the group's founder and conductor.
"He (Bachchan) jelled so well with the boys and he also appreciated the performance of the choral group. The rest is now for you all to watch on the opening episode of 'Kaun Banega Crorepati' on your TV screen Friday, " Nongkynrih told.
After meeting the acclaimed choral group, Bachchan wrote on his blog: "By far the most delightful moment of the day was meeting and seeing the Shillong Choir, a young group of boys and girls from the northeast, performing some wonderful renditions of ahah... cannot disclose all that just yet, songs. It was pretty 'goose bumps' material! Does anyone know why it's called 'goose bumps'?"
Earlier, SCC had performed for the US President Barack Obama when he was on India visit.
Formed in 2001, the SCC in its repertoire includes works of western classical greats Handel, Bach, Gershwin and Mozart and Khasi folk songs and own compositions. So far, the group has won three World Choir Games awards.