Internet of Things(IoT) has become a hot research topic recently. There are many research efforts aiming to tackle the challenges posed by IoT ranging from new protocol developments to Fog Computing for reducing the impact of IoT traffic on the Internet backbone. 6TiSCH is a new protocol being standardized by Internet Engineering Task Force (IETF) that aims to address many challenges that are inherited by IoT due to use of low power wireless devices. In this paper, analyze and report preliminary performance results of several well known Quality of Service (QoS) routines for 6TiSCH protocol. The QoS mechanisms are realized using the available 6TiSCH protocol stack within Contiki Operating System.