I have a targeted property I wish to purchase. Its NN lease. How to write a LOI and should a lawyer prepare it

Find a commercial RE broker in your area. Lawyers are expensive and typically know a fraction of what they think they know (especially when it comes to real estate).
A good broker can keep you out of trouble in the early stages of the transaction and will know when to interject an attorney. They are also more reliable on ascertaining market values for properties.

Karanbhai, Talk to people you know about this property, look at the location & similar properties in area sold to determine the fair market value. Most of the real estate is selling at 20-50% discount... hire a good lawyer from start its worth!..... I am a investor just like u, can help if needed

Hi Ravi,
Thanks for your reply. Can you give me your contact details at joy.smiling@gmail.com?
Thanks
Karan

I have a very good sample that I use. You can take it to your lawyer to alter. I can send it to you if you like. rockysg1@yahoo.com

No need for a lawyer on an LOI. An LOI is not a binding contract, it's more of a starting point for negotiations. If there is an appropriate time to bring in an attorney, it would be when you actually put together the purchase and sale agreement (contract).
I'd recommend speaking with a qualified commercial broker in your area.

Yes a broker would probably be your best bet and you might get a better price with one. Also they are paid on commission by the seller and does not cost anything to you whereas an attorney will. Email me at tnguyen@naicapital.com if you have questions.