My mom is donating her kidney 2 her brother 1 kidney is having 2 arteries , other is having 3 arteries.is it safe to go for multiple artery transplant?

Yes , they can : The transplantation team has the skills to handle this kind of situation , they will attach these arteries , speak to them about your concern , will get the explanation to make your mind at ease.

Usually yes: There are a number of surgical considerations if there are multiple arteries in the kidney, primarily their size, whether going to the upper pole or lower pole etc. Talk to your donor surgeon. Most of the time it is possible to use a donor kidney with two arteries.