How long after flood of Noah's day was Nimrod around?

The flood of Noah's day occurred in 2370 B.C.E. Genesis 7:1-16, Luke 17:27 and the Tower of Babel was in 2269 B.C.E. There is a total of 101 years between the two events. Nimrod was already an adult with a reputation and had become a King by that time so he must have been at least 20-30 years old or so.

Genesis 7:1-16, 24 reads:
7 After that Jehovah said to Noah: “Go into the ark, you and all your household, because you are the one I have found to be righteous before me among this generation. 2 You must take with you every kind of clean animal by sevens, the male and its mate; and of every animal that is not clean just two, the male and its mate; 3 also of the flying creatures of the sky by sevens, male and female, to preserve their offspring alive over all the earth. 4 For in just seven days, I will make it rain on the earth for 40 days and 40 nights, and I will wipe from the surface of the ground every living thing that I have made.” 5 Then Noah did everything that Jehovah had commanded him. 6 Noah was 600 years old when the floodwaters came upon the earth. 7 So Noah, along with his sons, his wife, and his sons’ wives, went into the ark ahead of the floodwaters. 8 Of every clean animal and of every animal that is not clean and of the flying creatures and of everything that moves on the ground, 9 they went inside the ark to Noah by twos, male and female, just as God had commanded Noah. 10 And seven days later the floodwaters came upon the earth. 11 In the 600th year of Noah’s life, in the second month, on the 17th day of the month, on that day all the springs of the vast watery deep burst open and the floodgates of the heavens were opened. 12 And the rain poured down on the earth for 40 days and 40 nights. 13 On that very day, Noah went into the ark along with his sons, Shem, Ham, and Ja′pheth, and his wife and the three wives of his sons. 14 They went in with every wild animal according to its kind, and every domestic animal according to its kind, and every creeping animal of the earth according to its kind, and every flying creature according to its kind, every bird, every winged creature. 15 They kept going to Noah inside the ark, two by two, of every sort of flesh that has the breath of life. 16 So they went in, male and female of every sort of flesh, just as God had commanded him. After that Jehovah shut the door behind him. 24 And the waters continued overwhelming the earth for 150 days.

Luke 17:27
they were eating, they were drinking, men were marrying, women were being given in marriage until that day when Noah entered into the ark, and the Flood came and destroyed them all.

Noah was the first patriarch of the post-Flood society. (Genesis 10:1-32) Nevertheless, during his lifetime false religion again rose up among those under the leadership of Nimrod, as is seen in their rebellious attempt to build “a tower with its top in the heavens” for fear that they might be scattered “over all the surface of the earth.” This was in direct opposition to God’s command to “fill the earth,” and was a rebellion also against Noah’s position as God’s prophet. Noah died about two years before the birth of Abraham. He therefore got to see Jehovah’s judgment on the builders of the Tower of Babel and the scattering of those rebellious ones over the face of the earth. Noah and Shem were not involved in the tower building and consequently would not suffer confusion of their language, but would continue to speak man’s original language, which God gave to Adam.—Genesis 9:1, 28, 29; 11:1-9.

The Tower of Babel has traditionally been depicted as a type of ziggurat, although the Bible doesn’t give specific dimensions. Interestingly, this word means tower but figuratively reflects a flowerbed that yields a pyramidal shape. This gives a little support to the idea that the Tower of Babel may have been pyramidal or ziggurat shaped.