what i need to do when it shows you have reached the limit of allowed tabs for your organization

Hello @Venkata prasad Nelapati you will probably need to upgrade your Salesforce edition

source : https://help.salesforce.com/s/articleView?id=000387641&type=1

Your Account Executive can help you increase the number of Custom Tabs allowed.

The maximum number of Custom Tabs available varies per Salesforce edition:

• Contact Manager Edition: 3
• Group Edition: 5
• Developer Edition: 100
• Professional Edition: 1210
• Enterprise Edition: 1225
• Unlimited Edition: 1225 
• Performance Edition: 1225

Eric