Interest free loan

Yes u have absolute liberty to conduct ur business and ur life in the way u like.
for taxation one thing has to be kept in mind that u should not be claiming unecessary expenses which are not allocatable for ur business earnings.
if u have taken a loan from bank on interest and u further lend the same money to ur brother for no interest. then u arebineligible to claim that bank interest expense against ur business profits.

if u r lending out of ur personal capital then apparently there isnt any issue

Yes you can give loan to your brother's proprietory concern. Provided you should have given loan from your surplus money and not re-financed.

Today is your first day on Forum
What for you have joined Sir
This is the forum for your advertisement and better you shift to another Ad type Forum.

This is not right place for you.