Hey Sumithra Kondapaka,

Yes you need to submit your caste certificate at the time of document verification. Because they need to knew that you belong to that Category and based on that the income certificate is verified. According to that the fee reimbursement will be alloted to you. 

Below are the documents given that you have to submit at the time of doccument verification:

You need to submit All the original certificates and you need to submit the 2 sets of Xerox copies of the below given documents: 

TS ICET 2019 Rank CarD

TS ICET 2019 Hall Ticket

Aadhaar Card

Degree marks memos & pass certificate

Intermediate or its equivalent Memo-cum-Pass Certificate

SSC or its equivalent Marks memo

Intermediate or its equivalent Memo-Cum-Pass Certificate

Degree Memorandum of marks

Degree Provisional Pass Certificate

Study or Bonafide Certificate from IX class to Degree

Transfer Certificate (TC)

Income Certificate issued on or after 01-01-2019 by authority. 

Residence Certificate of the candidate for a period of 7 years preceding to qualifying examination in case where the candidate has no institutionalised education 

for more details about TS ICET counselling you can check here:

https://www.google.co.in/amp/s/bschool.careers360.com/articles/ts-icet-counselling/amp