The Indian Oil Corporation Limited (IOCL), Chennai, has committed to invest Rs 54,000 crore in various projects in Tamil Nadu in the next few years, including a 9 MMTPA (million metric tonnes per annum) grass-root refinery at an estimated cost of Rs 35,580 crore, its executive director and state head (TN & Puducherry) V C Asokan said here on Thursday.