Dear Neeran, I think you need to be made this question more clearer, so as to make necessary suggestions. In the same vein, if you need to identify bioactive compounds in your plant extract, I suggest that you used LCMS analysis.
You can use FTIR to detect some functional groups of majority compounds in extracts. Remember this technique evaluate bond interactions. So, you only will be able to suggest the possible presence of phytochemical families, not specific compounds. However, you could use some compounds (alkaloid, flavonoid, saponin,...) as patron.
Also, you could use the results to direct the chemical separation.