“18. It is well-settled that the use of word “may” in a statutory provision would not by itself show that the provision is directory in nature. In some cases, the legislature may use the word 'may' as a matter of pure conventional courtesy and yet intend a mandatory force. In order, therefore, to interpret the legal import of the word “may”, the court has to consider various factors, namely, the object and the scheme of the Act, the context and the background against which the words have been used, the purpose and the advantages sought to be achieved by the use of this word, and the like. It is equally well-settled that where the word 'may' involves a discretion coupled with an obligation or where it confers a positive benefit to a general class of subjects in a utility Act, or where the court advances a remedy and suppresses the mischief, or where giving the words directory significance would defeat the very object of the Act, the word 'may' should be interpreted to convey a mandatory force. As a general rule, the word “may” is permissive and operative to confer discretion and especially so, where it is used in juxtaposition to the word “shall”, which ordinarily is imperative as it imposes a duty. Cases however, are not wanting where the words “may” “shall”, and “must” are used interchangeably. In order to find out whether these words are being used in a directory or in a mandatory sense, the intent of the legislature should be looked into along with the pertinent circumstances.