query: How to register for CA Articleship online

As of now, ICAI hasn't provided any way to register for Articles online.
however, ICAI has been providing placements in Articles through an online portal, the details of which is given below

The Board of Studies of the institute has great pleasure in introducing an optional Articles Placement Scheme for selection of Articled Assistants by CA Firms. The scheme has been evolved to provide an opportunity to the firms of Chartered Accountants having vacancies for Articled Assistants to interact with the candidates who have either (a) Passed Group-I or both Groups of the IPCC examination , or (b) have been admitted under the Direct Entry Scheme and are eligible for undergoing articled training for selection as articled assistants in the C A Firms. This scheme at the same time, assists eligible students to get placement in CA Firms for their articles training. 

No Fee is to be Charged From the Participating CA Firms and Students registering on the Portal.

Guidelines for CA Students:

CA students who have qualified Intermediate (Integrated Professional Competence) Course Group-I or both Groups or have been admitted under the Direct Entry Scheme for Intermediate (IPC) Course, and are eligible for undergoing articled training can apply for registration through Portal. The participating firms would short list the candidates registered on the Portal as per their requirement and call the candidates for interviews/interactions as per date and time convenient to them at their offices. If the date and/or time given by the CA firm is clashing with date and/or time of other CA firm(s), the candidate concerned is required to intimate the other firm(s) about the clash of date and time and request the firm(s) to change the same as per mutual convenience. Candidates appearing for the interviews are required to carry proof of their identity along with a copy of the mark-sheet(s) relating to Intermediate (Integrated Professional Competence) Course Group-I or both Groups or Graduation/Post Graduation, duly attested by a Chartered Accountant or a Gazetted Officer. Each student who would be given letter by the CA firm for pursuing articled training is required to give acceptance to the firm within 7 days' time. In case the consent as per consent form is given by the Article to the firm this will be irrevocable from both sides and student will not be registered by ICAI under any other CA firm without the consent of the firm who were originally given the consent. After giving consent to the CA firm, he shall be required to indicate about his selection at the appropriate place on the Portal so that he should not be invited for further interviews by the CA firms. Students are advised to follow the proper Dress Code as prescribed by the Institute while appearing for interviews/interactions.