Hello Aleena Varughese

You should follow the TRIzol method for RNA isolation from cells. I have provided a detailed protocol in the link below.

https://www.researchgate.net/post/How_can_I_perform_Trizol_RNA_extraction_from_adherent_cell_line/1

If you are using suspension cells you may follow these steps:

a. Pellet the cells by centrifugation and discard the supernatant.

b. Add 0.75 mL of TRIzol reagent (per 5– 10 × 10^6 cells) to the pellet.

c. Pipet the lysate up and down several times to homogenize.

You may then continue from step 6 from the above protocol provided in the link.

Good Luck!