Is it permissible to open a letter of credit within the state in which they operate ? If yes? How and what the name of this dependence if not? Why?

no

because the letter credit is " the Purchasingof indirect order "

and it must be open between two (  companies ) not in same country

Agreed with colleagues answers

Agree whith your answer hany

We cannot open within a same country, because this is an arrangement only when a company is not sure of the receipt from another country.