Lamba's long term ambition was to become a journalist. While studying for a degree in Delhi, she was offered to represent ad campaigns like LG, Sony, Cadbury, Hajmola, Airtel, Sunsilk etc. During an ad shoot for Cadburyshe was approached by Bollywood director, Shoojit Sircar, who signed her to act in his film Yahaan (2005).
In 2008, she acted in Siddharth Anand's film Bachna Ae Haseeno. Her next major role was in the Shyam Benegal film Well Done Abba (2010), She has also played supporting roles in Corporate, Rocky: The Rebel, Anthony Kaun Hai, Honeymoon Travels Pvt. Ltd., Anamika, Shaurya and Dus Kahaniyaan.