Chichi~~~

https://www.mangago.me/read-manga/the_s_classes_that_i_raised/

https://www.mangago.me/read-manga/i_shall_live_as_a_prince/
https://www.mangago.me/read-manga/banana_fish/ (Not the main point of the.m story but MC does also want to advance his brother)
https://www.mangago.me/read-manga/ranker_who_lives_a_second_time/
https://www.mangago.me/read-manga/the_sword_of_glory/ This is father and son but thought it would fit

I can’t remember any more that are with actual brothers but I think have few more where they want to avenge someone *like* a brother to them but also few are side characters so let me know if you want them ^^

https://www.mangago.me/read-manga/the_100th_regression_of_the_max_level_player/ although not a main plot point in the novel, he's effort to protect his Lil bro are pretty prominent in the comic. Baby bro is VERY baby and actually deserve all the protection!!
https://www.mangago.me/read-manga/the_s_classes_that_i_raised/ MC Lil bro is his priority, keeping him alive, safe, get him to grow and live a normal life, that's the whole reason for him going back in time. He does treats him like he's 11 and not a full grown man/top 3 strongest awakeners in the country, but we'll live. Has a degree in excusing his wrongdoings.
https://www.mangago.me/read-manga/an_uncomfortable_truth/ you know that time the bts guy was getting backlash for doing something bad and a fan tweeted "my poor meow meow...my baby my little baby who hurt so much but treats people with nothing but kindness forgive me for not being able to do more..i tried my best i really did.."? That's the MC with his Lil brother.

This one too https://www.mangago.me/read-manga/bokura_no_ketsumei/

Thank you (⌒▽⌒)

Thank you so much (*^^*)

Arigathanks (^ー^)

https://www.mangago.me/read-manga/maou_jou_de_oyasumi/

Here is my directory Hope you find something you like
https://www.mangago.me/home/mangalist/2085943/