1) I presume that buy back of shares has been duly approved In the EGM called for by the company
2) if the company has issued letter of offer the company would be required to buy back your shares
3)send letter to the company that you are willing to offer your shares to the company ..
4) you can issue legal notice to the company to buy back your shares .
5) you can move CLB to direct the company to buy back its shares