Your mom can apply for L visa for Visiting Families
your brother working in China also should send some documents for your mother's visa application:
(1) Proof that you have a genuine ongoing relationship with the person inviting you in China (birth certificate) and the copy of valid resident permit

(2) Invitation letter from your brother

your mom should prepare the following documents:
(i) Original passport which has more than 6 months left before it expires from the date of application for a visa and sufficient blank visa pages.

(ii) One completed Visa Application Form (e-Form / Download) with a recently-taken passport photo; all the items on the application form should be completed neatly with genuine information;

(iii) Proof of sufficient finances to cover all expenditures in China when requied. From 16th March 09 Applicant holding Indian Passport applying for first time Tourist Visa Require to submit Original Bank Certificate with minimum balance of Rs 1.5 lacs.

(iv) Confirmed return flight ticket and its photocopy.

(v) Covering letter from applicant's company or office.

(vi) Photocopy of personal data page of applicant's passport.