Hello Sir!!
Greetings for the day
We understand that you come under the definition of profession as per section 44AA (i.e. Person carrying on legal, medical, engineering or architectural profession or the profession of accountancy or technical consultancy or interior decoration or any other profession as notified)
Further we assume that in rest of the 5 months the professional fees which you have received is not more than 50 Lakhs rupees in aggregate.
- You can opt for presumptive scheme u/s 44ADA only if you are covered under the above mentioned definition of profession, subject to 50 lakhs limit
For ITR’s it will get notified for FY 2018-19 i.e (AY 2019-20) only after completion of the financial year
2. For Advance Tax and Refund
For these first you need to compute tax liability and calculate tax payable, In case your tax payable is less than the taxes already paid (ie TDS credit for the whole FY in your case) you can claim refund in the return for the said previous year and if tax payable is more than TDS credit for that financial year, you will be required to pay advance tax.
Below is the link you can refer to make advance tax payment online
https://onlineservices.tin.egov-nsdl.com/etaxnew/PopServlet?rKey=-1513727846