To simplify the expression 10m^2 - [5m^2 - (2m^3x3 + 1)], we can start by simplifying the innermost parentheses first.

Inside the parentheses, we have 2m^3x3 + 1. Multiplying 2m^3 by 3 gives us 6m^3. So, the expression becomes:

10m^2 - [5m^2 - (6m^3 + 1)]

Next, we can simplify the expression inside the square brackets. We have 5m^2 - (6m^3 + 1). Distributing the negative sign inside the parentheses gives us:

10m^2 - 5m^2 + 6m^3 + 1

Simplifying further, we have:

(10m^2 - 5m^2) + 6m^3 + 1

Combining like terms, we get:

5m^2 + 6m^3 + 1

So, the simplified expression is 5m^2 + 6m^3 + 1.