Hello Aspirant, first of all make sure that you have successfully completed your first application form, i.e., personal/general information. There are three tabs to complete the first form:
• General Information
• Qualification details
• Declaration

After filling in all the details successfully, a login ID and password will be generated.

Now, fill in the second form: Course Application

• Click on 'Apply for Courses'
• Now choose the exam category and course you want to apply for.
In your case it would be:
Exam category - Common Entrance Test/ B.Arch/ Weekend Programmes
Course - PARA

Reason why you should choose "PARA" is :
There is an abbreviated name of the Common Entrance Test given by GGSIPU along with a CET code.
For following programmes a CET will be conducted:-
1. Bachelor of Physiotherapy (BPT)
2. Bachelor of Prosthetics and Orthotics (BPO)
3. Bachelor of Occupational Therapy (BOT)
4. Bachelor of Science (Medical Lab. Technology) (BSCMLT)
5. Bachelor of Audiology and Speech Language Pathology (BASLP)

And their CET code is 124.
And, CET abbreviated name is PARA.

• Each candidate has to pay a fee amount of ₹1000 for each course applied.
• After applying for the course of your choice, i.e., BPT. Now click on 'I Agree' and then 'Submit' your application.
• You will receive a message to preview the details provided in the second application. In case, you want to make any changes click on 'Cancel'.
• Make payment through the BillDesk. You can do it either through credit card, debit card or internet banking.
• A form will be generated incorporating all the necessary details, along with course details. So you must take a printout of this form for future references.

So once you are done with this process, you can check the course details. Also, if you want to apply for multiple courses, then you just have to login with the ID and password given earlier. And do the same process again.

I would recommend you you to check the "Admission brochure" and "FAQ: How to fill-up the online application form" on their official website:
http://www.ipu.ac.in/Pubinfo2019/Admission2019mian/adm2019main.htm

Last date to apply for your course is 29th April, 2019.

All the best!
I hope this helps.