should one participate in hexaware delisting? what if one doesn't participate in delisting? will i be able to sell later and if participate can we bid our delisting price?

If the price is good and you are getting a profitable exit, there is no reason you should not participate. AT the end of the day, if the company gets more than 90% of the non-promoter stake surrendered, the company can go ahead with delisting.

In such cases, the company can do a mandatory delisting and all the shareholders who have not yet surrendered are paid the price paid to all shareholders and their share holdings are cancelled. An important aspect is how minority shareholders of the company will react.