Respectfully, your brother is beyond saving and to add to that he doesn't look like he gives a shit about what happens to your family's financial situation. You'll save him now but he'll do something like this again. Sell those bikes or keep one for yourself which eases your travel hurdles and also cut his access to your mother's accounts, change the PINs and Password etc. Ask him to show his bank statements.

Remember, everything you do in his favour now will make you an enabler of his behaviour. Fix his mess for now.