@valli.sujankumar Thank you for that question. The term ‘satan’ in Hebrew simply means ‘the accuser’ or ‘the adversary’ - it is not a formal title. It is describing the role that ‘the accuser’ is playing Job - accusing Job before God. In Job the term ‘sons of God’ appears to clearly refer to angelic beings, though in Genesis 6 it may have another referent - the same term can have different meetings in different contexts.
Regarding when ‘the satan’ was cast out of Heaven, that would have been during Jesus’ earthly ministry or after His victory over the powers of evil upon the cross. So at this point in the Bible ‘the accuser’ still had access to the heavenly council.
The Lord grant you wisdom as you study. Are those thoughts helpful? Do you have further questions.
v. 6 - The “sons of God” refer to the angelic host (cf. Job 38:7). They constitute the heavenly council, God’s courtiers surrounding the throne ready to obey His every command. See also 1 Kings 22:19 and Daniel 7:9-14. With them was " the Satan ". Everywhere this word appears in Job it has the definite article (“the”; cf. 1:6,7(2),8,9,12(2); 2:1,2(2),3,4,6,7). Hence, it is a title, descriptive of his function and character. The word “Satan” literally means one who opposes at law, an adversary (seeZech. 3:1-2).
The “sons of God” in the OT is generally taken to refer to angels. They are not actually “sons” of Elohim ; the idiom is a poetic way of describing their nature and relationship to God. The phrase indicates their supernatural nature, and their submission to God as the sovereign Lord. It may be classified as a genitive that expresses how individuals belong to a certain class or type, i.e., the supernatural (GKC 418 §128. v ). In the pagan literature, especially of Ugarit, “the sons of God” refers to the lesser gods or deities of the pantheon. See H. W. Robinson, “The Council of Yahweh,” JTS 45 (1943): 151-57; G. Cooke, “The Sons of (the) God(s),” ZAW 76 (1964): 22-47; M. Tsevat, “God and the Gods in the Assembly,” HUCA 40-41 (1969/70): 123-37.
The NET Bible
Sons of God in Genesis 6
The term ‘sons of God’ also appears in Genesis 6 and has three possible interpretation:
1 - descendants of the line of Seth
2 - angelic beings
3 - tyrants