Taiwan visitor visa expiring before date of visit?what to do?

My visitor visa is valid till 21 MAY and my date of visit is in JUNE. Please advise me what to do… Should I wait till the expiration of the current visa or Should I re-apply before that. One more thing I want to ask would it required to show them the reason of not using the visa??
I am INDIAN national getting the TAIWAN visa.

You shouldn’t need to wait for the expiration of your current visa to apply for a new one. If you already have travel plans, get a copy of the ticket or itinerary and apply for the new visa.

thanks for the reply…
Is it necessary to attach the return tickets because dates are not fixed but its in the month of June…???

They might be wary of issuing a tourist visa if you only show them a ticket to go to Taiwan, but not leave.