Text input process in Indic scripts is complex due to the large set of complex characters and more number of user actions required to enter a syllable. Research objective is to identify and evaluate the effective ways of text input in Indic scripts on mobile devices through usage of multimodal interactions. Scope of this research includes identifying various problems faced by the users in entering Indic language text on touchscreen mobile devices, theoretically analysing few of these problems, and designing solutions for some of those through appropriate use of multimodal interactions. The overarching objective of this proposed research work is to contribute towards making the text entry in Indic script on mobile devices easy and faster. This doctoral thesis is under the supervision of Prof. Anirudha Joshi and is a part of the on-going research on Indian language text entry at IIT Bombay, India.