You can pay advance tax for FY 2018-19 and it will reflect in your Form 26AS in tax paid details, but it will take 7-10 days to reflect there from the date challan is submitted.
You can't pay tax against your deductor because even if you pay such tax for your deductor he needs to file TDS return and needs to show that for whom such TDS has been deposited.
Generally no one pays advance tax in case of salaried employee as TDS deducted is enough for a salaried employee but if your employer is not deducting TDS then you can pay advance tax in your own PAN so that you don't have to pay interest on such tax amount.
You can pay it in installments but if you pay it lump sum then I would suggest you to pay it in the June quarter only of the financial years because if you pay it in March you will have to pay interest u/s 234B for not paying proper installment.
In income tax there is interest for both:
1 for not paying proper installment u/s 234B
2 for not paying 90% of advance tax till March u/s 234C
Hope you find the information helpful if you do please rate it 5 and provide your valuable feedback for my improvement
Thank you