She took out a riba based loan and she wants to go for Hajj using her salary

It is haraam
to take riba-based loans, and the one who has done that has to repent to
Allaah and regret committing this grave sin. He should hasten to pay off
this loan and get rid of riba and its effects. He does not have to pay off
anything but the capital; as for the haraam interest, it is not permissible
to pay it unless he fears that he may be harmed, in which case he should pay
it because he is forced to. 

See the
answer to question no. 60185. 

Secondly: 

This woman
may go for Hajj using her salary, as her salary is part of her wealth that
she owns, and it is permissible if it is in return for permissible work. 

Thirdly: 

If this debt
is to be repaid in installments and her travelling for Hajj will affect the
payment of these installments, then she does not have to go for Hajj, rather
she must start with paying off the debt first, then go for Hajj. If her
travelling for Hajj will not affect the payment of these installments, then
there is nothing wrong with her going for Hajj, but if it is a
supererogatory (naafil) Hajj and she has already performed the obligatory
Hajj, then it is better for her to pay off this debt so that she can get rid
of this haraam riba. 

And Allaah knows
best.